Born on a farm there, where his father raised horses, King Leatherbury graduated from the University of Maryland with a degree in business administration then chose a career in thoroughbred racing. As a trainer, he won his first race in 1959 at Florida's Sunshine Park but made his reputation at racetracks in his native Maryland. He was the leading trainer at Delaware Park Racetrack on four occasions, won twenty titles at Laurel Park Racecourse and another twenty-five at Pimlico Race Course. He led all Maryland trainers in wins for four straight years between 1993 through 1996 and has won five races in one day four times and on another occasion won six races on one card.
