Leonard H. McCoy, MD, chief medical officer aboard the USS Enterprise, was born in Georgia, Earth, in 2227, and graduated from the University of Mississippi.
McCoy’s graduation date from med school at Ole Miss was never confirmed in a Star Trek production, but with four years of pre-med followed by four years of medical school, McCoy would normally have received his medical degree in 2253, assuming he started college at the age of eighteen in 2245. Kirk’s statement in 2270 that McCoy had been a doctor for twenty-five years seemed to support this. While in medical school, McCoy and his friends often played practical jokes on each other, substituting real drinking glasses with tricklers.
In 2245, an interplanetary gymnastics competition was hosted by the University of Mississippi and held at the Menlo T. Hodgkiss Memorial Gymnasium on the Oxford campus, where he met the Tr’i’ll Emony Dax, who was visiting Earth to judge the competition. According to Dax, McCoy “had the hands of a surgeon”. (While there isn’t a Hodgkiss Gym located at the present-day University of Mississippi campus, it is described in the series as “a relatively new” building, though on a 400-year-old campus, it’s impossible to speculate how old that might be, and currently the University of Mississippi’s School of Medicine is at the University Medical Center in Jackson, MS.)
McCoy met his future (ex) wife Pamela Branch at Ole Miss when she suffered brain-freeze from an ice cream cone. Branch wore white at the wedding ceremony and adopted the last name McCoy. She divorced him in 2255 because their professions kept them apart too often. In the divorce, she acquired their house on Mars, six cars and a valuable Vulcan painting. Leonard said that the divorce left him with nothing but bones (thus his nickname, “Bones”). Shortly afterwards McCoy enrolled in Starfleet Academy.
The rest, as they say, is history.