Leonard McCoy

Leonard Horatio McCoy was a human Starfleet officer, best known for serving aboard the USS Enterprise (NCC-1701) and USS Enterprise (NCC-1701-A) as chief medical officer.


 * The Crucible novel Provenance of Shadows established his middle name "Horatio." Various publications referred to McCoy as "Leonard Edward McCoy", even after Star Trek III: The Search for Spock established McCoy's middle initial as "H." 

=History=

Family
Leonard H. McCoy, the son of David Andrew McCoy and Eleanora McCoy, was born in Atlanta, Georgia, United States of America, Earth on 20th January 2227. His grandfather, Thomas Jackson "T.J." McCoy, M.D., was the Chief of Medicine at Emory University Medical Center in Atlanta in the 2220s.

One of his great-uncles was a proprietor to one of the top productive plantations in the South during the 19th century. His ancestor's advantage was a self-mixed form of herbicide. McCoy still had the recipe on Enterprise, and synthesized the concoction in his lab. He later used the "weed spray" to immobilize the swoopers of Phylos.

One of McCoy's grandmothers lived in Tennessee, where she taught Sunday school.

Early Years
In 2231, at the age of four, Leonard accompanied his father on a trip to Aberdeen, where he briefly met young Montgomery Scott, thus giving birth to not only their shared tastes (such as alcohol), but their smooth delivery in performing as scientist and assistant on 20th century Earth. The two also had done a convincing act while on the android world of, and when on jury duty during the Kirk/Lester trial. (SS TOS (Bum Radish: Five Spins on a Turquoise Reindeer),, , )

Disaster struck McCoy at the age of seven on August 17, 2234, when Leonard and his cousins built a raft and sailed down the Chattahoochee River. Leonard's cousin, David McCoy drowned when the raft broke apart. 

In September 2236, Leonard, aged nine, and his family moved into another southern town on Earth. Leonard met Mark Rousseau at school, and the two became best friends. The two parted in 2243 when Rousseau entered Starfleet Academy. At the time McCoy was determined to enter medical school. 

In 2238, at age eleven, Leonard ate something that was still alive on a dare. 

While in Texas in 2243, McCoy was thrown from the horse that he had been riding. McCoy suffered a concussion and bruised ribs, and was treated at a hospital in Waco, Texas. After suffering another head injury in 2268, McCoy briefly forgot everything that had occurred from the time of the first accident until the time of the second accident. 

At sometime during his childhood, McCoy attended one of the last religious "revival" meetings held on Earth, led by a preacher who railed against non-human races. This man later made an attempt on the life of the Andorian ambassador. 

McCoy first became attracted to his future wife, Jocelyn Darnell, at a high school social in early 2244, when Jocelyn forced McCoy to dance with her to counter the jealousy of her over-possessive boyfriend, Clay Treadway. Treadway brawled with McCoy there on the dance floor, but McCoy knocked him down and left with Darnell. This began their relationship. 

In late 2244/early 2245, McCoy, aged 17, entered college at the University of Mississippi ("Ole Miss"). During his time there, his roommate was a Tessma, Sinnit Arvid. In 2245, McCoy met the Trill, Emony Dax at a gymnastic tournament in the Menlo T. Hodgkiss Memorial Gymnasium, and the two had a brief relationship. Undecided at the time on his choice of career, Dax suggested he should be a doctor, because he had "the hands of a surgeon." (SS DS9 (Old Souls); )


 * Startrek.com places the year as 2245 for McCoy starting at the University of Mississippi.

Later that year, McCoy served as an observer aboard the USS Hood (NCC-1703) before officially enrolling in medical school, though he studied at his home in Georgia. 

While he was a medical student, McCoy often took skiing trips to the Alps in Europe. 


 * Startrek.com states that McCoy's med school time was from 2249 to 2253.

Shortly after receiving his doctorate, McCoy married Jocelyn, and around 2249, their daughter, Joanna McCoy was born. 

In 2249, McCoy commanded an inoculation program to combat a virus on planet Dramia II. However, when the team left, a plague broke out, wiping out half the population. It was his second extrasolar assignment and his first medical command. 

Later in the 2250s McCoy met a Lieutenant Clark Terrell. The two were friends until the latter's death in 2285. 

Aboard the Republic
In 2253, after Jocelyn left with Joanna (presumably before becoming involved with Clay Treadway once more), McCoy grew extremely depressed, and by chance saw an advert for Medicine on the cutting edge - Practicing in space. He immediately signed up at the Jackson Mall, entered Starfleet and underwent the course, which was taught by Angelina Mola, before he was assigned as a junior medical officer aboard the USS Republic (NCC-1371) under the command of Captain Hillios. McCoy worked in sickbay under chief medical officer, Vincent Bando. While aboard the Republic, McCoy saved the life of a ruthless assassin on the planet Ssan.

Aboard the Richard Feynman
In 2254, thanks to McCoy's excellent work on the Republic, he was made chief medical officer aboard the USS Richard Feynman, under the command of his old friend, Mark Rousseau. However, following a fall-out with Rousseau, McCoy accepted a demotion as a junior medical officer aboard the USS Koop.

Aboard Starbase 7
By 2255, McCoy transferred to Starbase 7 as chief medical officer. A few months later, Lieutenant James T. Kirk, of the USS Farragut (NCC-1647), was sent to the base for rehabilitation after Kirk was badly injured battling pirates from Epsilon Canaris III. In Kirk's many months at the base, McCoy and he became good friends, and Kirk visited McCoy's home on Centaurus many times.

While on Starbase 7, McCoy also had a brief relationship with a woman named Nancy Pagano, who later married Professor Robert Crater.

Aboard the Constitution
In 2257, McCoy transferred aboard the USS Constitution (NCC-1700) to work under chief medical officer Christina Velasquez. Also serving aboard the Constitution at that time was McCoy's old friend, Lieutenant Commander Kirk.

Starfleet Teaching Hospital
McCoy returned to Earth in 2262, and took up a position at Starfleet Teaching Hospital working with Dr. Carol Marcus and Christine Chapel. In late 2263, Captain Kirk and Lieutenant Commander Gary Mitchell were placed under McCoy's care after the destruction of the USS Lydia Sutherland at the Battle of Ghioghe. 

The Three-Month Voyage
In 2264, McCoy accepted Captain Kirk's offer to become Chief Medical Officer aboard the USS Enterprise (NCC-1701). 

''According to the elder Spock in, "In both our histories the same crew found its way onto the same ship in a time of ultimate crisis." This may imply that there is an untold story set in the prime timeline in which Kirk's crew faced an extremely serious challenge while still a new and untested unit.''

McCoy's first stint aboard the Enterprise was cut short when he learned that his father was dying of pyrrhoneuritis. McCoy took an extended leave of absence to look after his father, and was replaced by Dr. Mark Piper. 

A memory that would haunt McCoy for years was when, at the request of his father, he turned off all his life support, allowing his father to die with dignity. However, a few weeks later, a cure for pyrrhoneuritis was developed. 

Mission to Capella IV
Following the death of his father, McCoy was asked by Starfleet Medical to take part in a medical relief mission to Capella IV. He gratefully accepted, to get as far away from Earth as possible and to help others. However, by 2265, he was tired of locking horns with the Capellans, who refused any modern medical technology.

Return to the Enterprise
Luckily for McCoy, the Enterprise had returned to Earth for the funeral of Gary Mitchell, so when Kirk offered McCoy his old position as CMO back, McCoy jumped at the chance. 

Jocelyn Darnell sent McCoy their divorce papers in 2266, and McCoy signed them without a fight. Although he would go on to refer to Darnell as "whatsername" and worse, he wore his wedding ring for the rest of his life. 

While in a Cordrazine-induced frenzy in 2267, McCoy jumped through the Guardian of Forever and was transported to Earth in the year 1930. While there, the shape of time itself hinged on his actions, resulting in a drastically altered timeline when he saved Edith Keeler from a fatal traffic accident. Although time later resumed its normal course, the phaser McCoy had brought with him was stolen by "Rodent," a Twenty-First Street Mission resident, who was vaporized along with the weapon when he inadvertently triggered it. Later the same year, while serving aboard the Enterprise, McCoy was accidentally transported into the mirror universe. McCoy risked being left behind in the parallel reality to save the mirror version of $𝜇$ from a fatal subcranial hemorrhage. Spock then mind-melded with McCoy, and learned about the Federation of the regular universe. McCoy returned successfully to his own universe, but Spock's visions of a better reality would be passed on to multiple Vulcans in the mirror universe, and lead to a secretive resistance group against the Klingon-Cardassian Alliance. 

The following year Doctor McCoy suffered a severe head injury after a gravity adjustment on the Enterprise caused him to fall and hit his head on a bulkhead. Even though Dr. Eduardo Cortejo Alvarez was able to operate almost immediately, McCoy was still left with severe amnesia for a period of about two weeks. During this time he had lost all memory of the past twenty five years, including his prior service on the Enterprise and his relationships with colleagues such as Captain Kirk and Mr. Spock. After Spock was seriously injured and required surgery, the impact of watching Spock dying on an operating table was enough to bring Dr. McCoy out of his amnesiac state, and McCoy was able to save Spock's life. 

In 2269, McCoy accompanied Captain Kirk, Spock, and Crewman Alonzo to one of the planets in The Strand where they met Dr. Othello Beck. A few minutes after he arrived, McCoy examined Alonzo's corpse after he was killed by a B'Nai. McCoy then examined Beck's discovery. Unfortunately, he and Kirk were captured and put into cell when they found out about Beck's wife's Logan's disease. They were however able to escape and return to the Enterprise. McCoy then went to a reception on Aarak 3 after trading technology for mining dilithium. McCoy was able to throw a bomb away from them and King Marat. McCoy then agreed that they could interfere with Aarak's situation between Marat's government and the traditionalists, despite the chance of losing of the dilithium. McCoy then accompanied Spock in his search for Kirk on Aarak 3, to which they were successful. 

McCoy and the Enterprise were then sent to investigate Phi-11. There he found all the colonists were dead. McCoy and the rest of the ship was affected by a viral lifeform. McCoy, Spock and most of the crew mutinied against Kirk. They were then able to take the Enterprise and return the life form home. McCoy then went with the away team to the surface of Gobi III to find survivors of the USS Pasteur (science vessel). He and the away team were then captured by and place in holding cells. McCoy then examined Mallard and saw that avatar had strip-mined his DNA. McCoy was shocked that Avatar was treating babies as "merchandise" and that there was Human DNA. McCoy helped then Kirk hold off Avatar while Lt. O'Hara escaped with one of the babies. McCoy and the others were then able to return to the Enterprise. 

After McCoy and Scotty attended a biotechnology conference on Starbase 10, the USS Lexington (NCC-1709) dropped them off on Denebia for the Enterprise to pick up. They got drunk on s and engaged in a barroom brawl with some locals and a Klingon named Krong, but afterwards convinced Kirk to ferry Krong to another neutral planet aboard the Enterprise. On this occasion McCoy considered the possibility of leaving the Enterprise at the end of its five-year mission. He had learned the Vulcan nerve pinch, but kept this a secret from Spock. (SS TOS (Where Everybody Knows Your Name))

In 2270, McCoy went with Kirk and Ambassador Cassady to oversee the ceremony accepting Archenar IV into the Federation. McCoy then went to the surface to look for a leaf that could cure Blake's disease. McCoy and Pavel Chekov were captured by Crawlers. McCoy was then forced to treat the wounded crawlers. Afterward, McCoy resigned and retired from Starfleet. 

McCoy then joined the Federation's Frontier Medic Program using an antiquated starship that he named after his daughter, Joanna. Alongside fellow doctor, Jon Duncan, and Theela went to worlds such as Omicron Testus IV, Ophiucus III, and Gamma Tarses VII where met up with Chief Engineer Montgomery Scott. McCoy, Duncan, and Theela, after the Joanna was destroyed, met up with Gary Seven and Roberta Lincoln at a planet inhabited by clones from the US Army in the 1960s. There they stopped Klingon commander Kloor from exploiting the human clones for war games. He was then rescued by the USS Yorktown (NCC-1717) under Captain Pike's former first officer who was now an Admiral and its CMO, Christine Chapel. At least two and a half years later, he was "drafted" (as McCoy himself once put it) back into service for the V'Ger mission. 

In 2273, after the  Enterprise' s shakedown cruise, McCoy helped escort ambassador R'Kgg and then recapture prisoner Raytag M'Gora. McCoy then went to Captain Kirk and Spock to investigate a "Haunted house adrift in space. After beaming in, they then heard a woman. McCoy then saw Frankenstein's monster strangling her. McCoy and the others tried to stun it to no avail. At first McCoy wanted to study it, but was forced to kill it. After the creature was pushed out a window. McCoy then saw the girl run towards them. It then dissipated and Klingons came and captured them. Kirk, McCoy, the girl and the rest team were able to escape despite Spock being captured by the Klingons. After the Klingons left, McCoy questioned the girl with little success. Back onboard the Enterprise, his analyzed his tricorder readings and realized that she was not Human. He informed Kirk of this.

In 2276, McCoy was placed in temporary command of the Enterprise by Captain Kirk after complaining too much about how the ship should be run. Captain Kirk beamed down to a planet known as Flyspeck to engage in a routine diplomatic mission. Intending to leave McCoy in command only for one afternoon, Kirk did not realize that he had been transported ahead in time one week. Unable to locate Captain Kirk, McCoy was forced to remain in command of the Enterprise for the week. Complicating the search for Kirk was the arrival of Klingons who had their own designs on Flyspeck, plus having to deal with an Admiral who had a reputation for being difficult. When Kirk realized that he had been transported ahead in time, he asked to be returned to the Enterprise so that McCoy could return command to him. 

2285
In 2285, Khan Noonien Singh escaped from the surface of Ceti Alpha V on board the USS Reliant (NCC-1864). Khan went to find James T. Kirk and take revenge against him for leaving him on Ceti Alpha V and not bothering to check on Khan's progress. Khan managed to seriously damage the Enterprise. Khan then took the Genesis Device from the underground laboratory on Regula. In a deadly game of cat and mouse, Kirk finally defeated Khan in the Mutara Nebula, however in a last ditch effort to destroy Kirk, Khan set the Genesis Device to explode. The Enterprise was only able to escape when Captain Spock sacrificed himself to bring the warp drive back on line just before the Genesis Device exploded. 

Just before Spock had entered the radiation-soaked dilithium chamber, he entered into a mind meld with Dr. McCoy, and transferred his katra into McCoy's mind. Spock's body died shortly after the Enterprise escaped the detonation of the Genesis device, however Spock's consciousness was still alive in the mind of Leonard McCoy.

McCoy stayed on the Enterprise as its Chief medical officer despite the loss of Spock. McCoy then treated the wounded after the Klingons' attacked near the Neutral Zone. He also gave the current science officer, Lieutenant Saavik, some advice on how to meet Kirk's needs. He then told Kirk not to push Saavik too hard. When Kirk, Saavik and the away team returned with Klingon defector Konom, McCoy, despite never operating on one, did so none the less. McCoy was surprised to hear that the Federation and the Klingon Empire had entered into a state of war against each other. 

In the weeks after Spock's apparent death, McCoy began behaving strangely. As the Enterprise docked in spacedock, McCoy broke into Spock's quarters. This tripped a security alarm on the bridge, and Admiral Kirk went to confront the intruder. Kirk was shocked to find McCoy in the quarters, who asked Kirk why he had been left behind on Genesis, and requested that Kirk climb the steps of Mount Seleya on. A horrified Kirk called for medics to be brought to Spock's quarters when McCoy collapsed in his arms. McCoy was examined and it was believed that he was suffering from exhaustion. McCoy promised Kirk that he would stay at his home on Earth for the time.

Sarek soon arrived on Earth and revealed the possibility that Spock's katra might have survived. Sarek did not find the katra in Kirk's mind. The two searched through engine room recordings, and discovered that McCoy was carrying Spock's katra. Sarek asked Kirk to retrieve Spock's body and bring the body and Dr. McCoy to Mount Seleya, claiming that it was the only way both could find peace. Learning that he was suffering from the effects of a Vulcan mind meld, McCoy stated that it was the "green blooded son of a bitch" getting revenge for all the arguments he had lost over the years.

When Starfleet Command refused to allow McCoy, Kirk, and the remaining senior staff of the Enterprise to return to the Genesis Planet, Kirk and his senior officers stole the Enterprise. En route to Genesis, McCoy took the science station, and using Spock's skills was able to use the scanners to determine that there were no vessels pursuing the Enterprise. After arriving at Genesis, they learned that Spock's body had been regenerated by Genesis. Kirk and his crew managed to defeat Commander Kruge. However, they lost the Enterprise in the process. Spock's body had reached the same age as it was just prior to his entering the dilithium chamber of the Enterprise at this point.

After being beamed on board Kruge's Bird-of-Prey, the crew of the late Enterprise proceeded at best speed to Vulcan. Arriving at Vulcan, the crew climbed the steps of Mount Seleya, where Sarek requested that the Fal-tor-pan be performed on Spock. Agreeing to this request, the High Priestess T'Lar performed the Fal-tor-pan, removing the katra of Spock from McCoy's mind and refusing it into Spock's body. 

2286
Over the next three months, Captain Spock recovered his memories. Spock and McCoy underwent a number of mind melds to ensure that any remaining vestiges of Spock were transferred from McCoy back to Spock. Despite losing memories of his past life, Spock remembered Kirk's first name as "Jim", to his own fascination. Which McCoy warmly smiled, pointing to his head, for his Vulcan friend.

McCoy named the captured Klingon bird-of-prey HMS in reference to the mutiny on board the British naval vessel nearly 500 years earlier. McCoy and the senior staff of the Enterprise all voted to return to Earth to face the consequences of traveling to the Genesis Planet to rescue Spock. Spock joined them, even though McCoy was concerned that Spock's recent experiences meant that he was not yet ready to resume his post.

On their way back to Earth, the Cetacean Probe arrived, searching for the humpback whales that it had lost contact with. The probe began reconditioning Earth, which endangered the population of Earth. To get the probe to stop damaging Earth, McCoy and the crew of the Bounty traveled back to 1986. While in the past, McCoy worked with Montgomery Scott and Hikaru Sulu went to find materials to enclose a tank on board the Bounty to hold humpback whales. The Bounty took the whales George and Gracie in to the 23rd century, where they managed to convince the probe to stop its assault on Earth.

After arriving back in the 23rd century, McCoy was concerned that he and Spock were not fully separated from each other, and that depending on his punishment he might not be able to participate in further mind melds with Spock. Spock reassured McCoy that the two men had been completely separated from each other. Though now the doctor had a better perspective in Spock's field of expertise. Understanding his problems with raw data inherent with time travel computation, he told him to make an educated guess. And that even though it wasn't in his nature to do so; no one is perfect. In a session of the Federation Council, McCoy learned that any charges against him had been dropped. The only punishment was directed at Kirk, who was reduced in rank from Admiral to Captain. 

2287
McCoy, a year later, once again told Spock no one is perfect after missing their target deck, in the escape from  Enterprise' s brig. He came to Spock's defense, reminding their captain that Spock could no more kill his brother Sybok than Spock could kill him, and that Spock is both Vulcan and human. McCoy stated that Spock never ceases to amaze him. Spock replied the same for himself. 

Later years
In 2293, the Enterprise-A was sent to escort a Klingon diplomatic party, led by Chancellor Gorkon, to Earth. During the encounter, it appeared the Enterprise fired photon torpedos at Gorkon's ship, damaging it. McCoy and Kirk then beamed over to the ship to see if the crew needed assistance. They discovered that Gorkon was dying and McCoy attempted to save the Chancellor, but was unsuccessful due to his lack of knowledge about Klingon physiology. McCoy and Kirk were then arrested and sentenced to serve a life term on Rura Penthe. With Spock's help, the two were able to escape the prison planet. Afterwards, McCoy helped Spock modify a photon torpedo to destroy General 's cloaked starship. 

In 2294, McCoy became seriously ill, necessitating the replacement of several organs by ones that had been cloned earlier and held in storage for such an eventuality. 

Likewise in 2294, McCoy served aboard the USS Enterprise (NCC-1701-B) in a temporary capacity as chief Starfleet medical advisor under the command of Captain John Harriman, during a crisis involving the release of Terrellian plague by renegade Klingon forces in the Antares star system. 

Also during this same year, McCoy tracked down his former crewmate, Montgomery Scott, and gave him a stern lecture about his solitary drinking, after Scott slipped into a depressed state following the loss of Captain Kirk. 

McCoy successfully recovered, and in 2296, was serving under Captain Spock on board the starship USS Intrepid II (Oberth class). 

Around the turn of the 24th century, McCoy joined the teaching staff at Starfleet Medical Academy. One of his students was Jo Stern, with who he would form a lasting friendship. Stern would call him "Mac," the only person he allowed to do so. 

At some point during the USS Enterprise (NCC-1701-B)'s time in service, McCoy served as her chief medical officer. 

In 2327, McCoy attended Sarek and Perrin's wedding on Vulcan. 

By 2336, he was working at Starfleet Medical. 

In 2344, McCoy escorted Spock and Saavik to their wedding ceremony. 

In the 2350s, he accompanied Spock to the Romulan Empire, where he met Eric John Stiles. 

McCoy retired from Starfleet in 2353.

In 2363, McCoy suffered an injury after tripping over one of his great-great-grandchildrens' toys which necessitated a stay at Bethesda Starfleet Hospital, preventing him from attending the launch of the USS Enterprise (NCC-1701-D). In "revenge", McCoy connived the USS Hood (NCC-42296) to take him to Farpoint Station, where they would be transferring crew to the new Enterprise. McCoy inspected the ship's medical facilities, and was escorted back to the Hood, via shuttlecraft, by Lieutenant Commander Data. McCoy told the young android the ship was new but had the right name, and that if she was treated well she'd always bring the crew home. 


 * The novel Provenance of Shadows has McCoy's death shortly after this tour, despite the contradiction of other stories.

By 2364, McCoy was 137 years old while his daughter Joanna was 115. 

McCoy revisited the Enterprise-D in 2367, and again in 2371. 

During this second visit, when assigned to assist the Enterprise in rescuing Spock from Romulus, McCoy attempted to take command when he felt that Picard was taking too long to negotiate for Spock's release, approaching the governor of the colony that had captured Spock directly rather than negotiating through the Romulan High Council. However, his actions actually made matters worse as the governor realized McCoy's identity and thus guessed that he had Spock prisoner, leaving McCoy feeling ashamed at the revelation that he had acted like the kind of arrogant admiral he had always hated in his own time on the ship, assuming that they knew better than the captain. However, a conversation with Guinan helped him move past this mistake, and he was later able to use his own knowledge to convince the Romulans to stand down after the unexpected intervention of the returned Scotty. 

Spanning these four years, his lifelong friend and colleague Spock asked him a personal question. Comparing the captains of Enterprise (1701,1701-A and 1701-D), which would McCoy summon in a time of need. He answered, in honesty, Spock himself. 

This, in fact, came true aboard the bridge of a starship. 

Spock swore to secrecy his choice of command; not even to share with Saavik, lest McCoy totally deny it. 

During this period, McCoy was also an occasional guest lecturer at Starfleet Medical Academy. 

By the late 24th century, McCoy was forced to have to wear an exoskeleton, including leg braces, although he later was given implants which allowed him to discard the exoskeleton. (SS TOS (Doctors Three);, )

In 2375, he assisted Kirk, Spock and Montgomery Scott in fighting the denizens of the mirror Universe before attending the wedding of Kirk and Teilani and setting out to find a cure when Teilani was poisoned by eugenic child 7. 

In 2376, McCoy joined in the celebrations surrounding Starbase 11. (SS ST (225 Years of Service))

In 2378, he and Spock, both wearing the current Starfleet uniform, retrieved an unconscious James T. Kirk from his battle with the Bajoran called Corrin Tal. 

In 2381, McCoy assisted in the Médecins Sans Fronti&egrave;res relief operation on P'Jem following the Borg invasion. As of 2381, Admiral McCoy was 154 years old. .

Alternate timelines
After traveling through the Guardian of Forever in 2267 to New York City in March 1930, McCoy saved Edith Keeler's life, an act which, unbeknownst to him, altered Earth history. McCoy spent two years in New York, expecting his colleagues to follow him back in time and rescue him. He placed numerous classified ads directed at Kirk and Spock in the hope that these newspaper records would survive into the 23rd century. By June 1932, however, he had become resigned to the fact that rescue was not coming, and he left New York and the Twenty-First Street Mission to re-establish a life for himself.

With little money, he jumped a southbound freight train, heading for his native Atlanta. On the way, McCoy was accosted by two other vagabonds, forcing him to jump from a moving train. He found himself in Hayden, South Carolina, badly injured and in need of medical attention. He encountered local resident Lynn Dickinson, who took him in and called on Doctor William Lyles to treat his injuries. Lynn and her husband, Phil, put McCoy up during his convalesce, and continued to board him for several weeks after, claiming McCoy as Phil's second cousin.

In November 1932, McCoy was compelled to perform an emergency tracheotomy, revealing himself to be a physician. Lyles, who had been initially suspicious of McCoy, offered him a partnership in his practice. When Lyles died of a heart attack in September 1934, McCoy took on his home and office and became Hayden's sole doctor.

In 1937, a rift formed between McCoy and Phil Dickinson after the doctor acted to defend an African-American man named Benny Russell from racist attackers. The incident also prompted Lynn to reconsider her own prejudices, and elevate her regard for McCoy.

McCoy was surprised when December 7, 1941, passed without news of the bombing of Pearl Harbor. He realized then that, because Edith Keeler had survived her brush with death years earlier, was able to become a powerful voice in the American Pacifist Movement and exert significant influence on the Roosevelt Administration, so much so as to delay or prevent the United States entry into World War II. McCoy confronted Keeler during a rally in Atlanta in late 1941, but was unable to sway her from her anti-war stance.

By 1944, after London had fallen to the Nazis and Japan had conquered Australia and New Zealand, the Axis finally struck against the United States in Hawaii and drew the nation into war. Phil Dickinson enlisted in the Army, and was killed in action in Ireland in May 1946.

McCoy and Lynn grew closer in the years that followed, though McCoy insisted on keeping the relationship platonic. However, when the Nazis dropped an atomic weapon on Atlanta in 1954, at the same time Lynn was supposedly in the city, McCoy was moved to propose marriage.

In 1955, a Nazi fighter was shot down over Hayden and crashed on the edge of town. McCoy, while attempting to offer aid to the pilot, was stabbed and killed. 

In another alternate timeline in which John Frederick Paxton destroyed Starfleet Command and ended the talks for the Coalition of Planets in 2155, McCoy became a widower upon the death of his wife Jocelyn in 2246, only a month after the birth of their daughter Joanna.

Consequently, he raised Joanna single-handedly and the two developed an extremely close relationship. In 2264, shortly after Joanna began studying medicine at the University of Mississippi, McCoy embarked on a career in the United Earth Starfleet. He was assigned as the chief medical officer of the UESS under the command of Captain Christopher Pike following the retirement of his predecessor Phillip Boyce.

He assumed that position immediately before the Enterprise's mission to transport Lady T'Pol and Ambassadors Nancy Hedford and Garrett Tarses to Babel, where they were to petition the Interstellar Coalition for United Earth's admission into the organization. Unlike many Enterprise crewmembers including its first officer Commander James T. Kirk, McCoy approved of the mission.

After being easily defeated by Kirk in a game of chess in the Enterprise mess hall, McCoy casually suggested that T'Pol, the Vulcan former first officer and last surviving crewmember of the Enterprise (NX-01), would be able to provide Kirk with a challenge. In response to this comment, Kirk made his xenophobic attitudes towards the Vulcan abundantly clear, as did Lieutenant John Stiles. McCoy told them that he and his ancestors going back more than 20 generations were from Georgia, where Martin Luther King, Jr. had begun his career as a civil rights campaigner more than 300 years earlier. He argued that expressing bigotry for others based on their species was no different from harboring such feelings for other humans based on their skin color. As he left the mess hall in disgust, McCoy could see that he had made Kirk furious but believed that he may have at least given him food for thought. This assessment was later proven correct.

While treating the injured Captain Pike in sickbay several days later, McCoy once again exhibited his tendency to be extremely plainspoken with his superior officers. Although Pike had never refused a request from one of his officers to speak freely, he appreciated being asked. However, McCoy's candidness reminded him of Boyce and, before returning to the bridge, Pike expressed his hope that McCoy would likewise become one of his closest confidants. 

In another alternate timeline in which the Vulcans had remained a violent and emotional species, McCoy served as the chief medical officer of the IUES, a starship of the Interstellar Guard in service during the late 23rd century. He was succeeded by Jabilo M'Benga.