Leavitt was born in New York City, the son of John McKenney Leavitt and Henrietta N. Leavitt. From childhood, Leavitt was above average in size and strength. This led to a lifelong interest in competitive sport, and also enabled him to lie about his age in order to join the Army at the age of fourteen. While enlisted he saw duty on the Mexico–United States border with John J. Pershing, and was later sent to France where he participated in combat during World War I. Also during this period he began his wrestling career using the ring name of "Soldier Leavitt".
Post World War I career
After the war, Leavitt embarked on a career in athletics. Although he played with the New York Brickley Giants of the National Football League from 1919–20, he concentrated most of his efforts on professional wrestling. He competed in the ring for a time under the name "Hell's Kitchen Bill-Bill" but eventually settled on the moniker of "Stone Mountain". Leavitt wrestled with limited success at first, and after an injury took a job as a police officer in Miami, Florida. Here he met his wife, Doris Dean, who also became his manager. At her suggestion, in 1932 he adopted the nickname "Man Mountain" and substituted the more Anglo-Saxon-sounding last name of Dean. At a stocky 5'11" and weighing over 300 pounds, Dean was an imposing figure. He also grew a long, full beard as part of his ring persona. After a successful wrestling tour of Germany which had been booked by his wife, Doris Dean, he was invited to take a job in the UK as stunt-double for Charles Laughton in the movie The Private Life of Henry VIII. This would be the beginning of a subsidiary movie career for Dean, who would appear in various roles in twelve other movies, playing himself in five of them. One of the movies in which he portrayed himself was the Joe E. Brown comedy The Gladiator, a 1938 adaptation of Philip Gordon Wylie's 1930 novel Gladiator. Meanwhile, he continued a successful wrestling career, participating altogether in 6,783 professional bouts and commanding fees upwards of $1,500 for each match. In 1940 he retired from the ring to a farm outside of Norcross, Georgia. Dean ran for a seat in the Georgia House of Representatives in 1938 but withdrew his candidacy, citing discomfort with the political process. During World War II he again joined the Army despite his age, and eventually retired with the rank of master sergeant. In the 1940s he was the First Sergeant of the Military Intelligence Training Center at Camp Ritchie, Md. Afterward he studied at the University of Georgia's school of journalism. He appeared as a guest on the December 29, 1944 episode of the radio programIt Pays to be Ignorant. During the program, broadcast from New York City, Dean gave his weight as 280 pounds. Several other wrestlers would go on to use the "Man Mountain" moniker, including Man Mountain Mike and Man Mountain Rock.
Death
Dean died of a heart attack in his home in Norcross, Georgia, aged 61, in 1953, and is buried in Marietta National Cemetery under a military marker bearing his birth name and an erroneous year of birth.
