Foster was born in Alexandria, Virginia, a son, and the third of eleven children, of a Mississippisharecropping family. He spent his childhood years in Fresno, California, where his father found employment as a nurse. Foster picked grapes and cotton as a youth. Fresno State University offered him a track and field scholarship out of Washington High School, but he declined the opportunity, choosing instead to enlist with the United States Marines. Whilst serving with the Marines he won fourteen amateur boxing titles, and was deployed for two combat tours in the Vietnam War. After a discharge from the Marines with the rank of sergeant, Foster turned professional, becoming the third Fresno boxer of note. He trained with Pat DiFuria at the Merced Street Gym.
Boxing career
Standing at 6 ft 2" in height and known as "Big Mac The Knife from Fresno", Foster made his professional debut in 1966, winning his first 24 fights by knockout, and was named The Rings Progress of the Year for 1969. Britain's Boxing Illustrated wrote, "He could certainly whack!" Whilst being employed as a sparring partner for Sonny Liston, Foster was reputed to have knocked down the former world champion, causing Liston two days later to work Foster over during another sparring session before handlers could intervene between the two men to stop it. In 1969 Foster knocked out contender Thad Spencer in the first round, and twice knocked out a past his prime Cleveland Williams. By 1970 Foster was ranked as the world's number one heavyweight contender and seemed set for a title shot, but his 24–0 winning streak came to an end when as favourite he was stopped in six rounds by the more experienced Jerry Quarry in June 1970. After the Quarry fight, Foster knocked out ageing but well rated Zora Folley in one round. In April 1972 Foster faced Muhammad Ali in Tokyo in a rare 15 round non-title bout. Although he beat Ali's prediction of a fifth round stoppage by lasting the distance, Foster lost a clear decision to the former champion. Foster followed up his loss to Ali with knockouts of journeymen Sam McGill and Charles Williams. He was then outpointed by Bob Stallings, Joe Bugner and Henry Clark in consecutive bouts. Foster served as George Foreman's sparring partner for Foreman's world title bout with Ken Norton in 1974. He retired from boxing in 1976 after losing his fourth consecutive decision, this time to prospect Stan Ward. Foster's final record was 30–6, with all 30 of his wins coming by knockout.
Later life
After retiring, Foster volunteered his time as boxing coach for youth.
