According to The Associated Press:
Patterson, who suffered from Alzheimer's disease and prostate cancer, had been hospitalized a week earlier. Funeral arrangements are pending. A second wife and four grown children from two marriages survive him.
Born in Waco, N.C., Patterson became a boxing phenomenon while competing in the New York Golden Gloves tournament. He later won gold as a middleweight in the 1952 Olympics in Helsinki, Finland.
In 1956, he knocked out legendary boxer Archie Moore in a pro title fight and became the youngest world heavyweight champion in history at age 21. He held the title for five years, and he won it again after a loss, making him the first heavyweight to reclaim the title.
He retired in 1972 at age 37 with a pro record of 55-8-1 and 40 knockouts. He went on to become New York state athletic commissioner.