Williams served with the United States Army during World War II in an all-African-American unit under General George S. Patton, Jr. and advanced to the rank of Staff Sergeant. He was the only survivor of a Nazi bombing, which left him in a hospital in Europe for more than a year and earned him a Purple Heart. Upon his return home from the war, Williams was savagely beaten by a group of angry whites at a bus station for drinking from a water fountain marked "Whites Only." He was beaten so badly that the attackers thought he was dead. They called a black funeral home in the area to pick up the body. En route to the funeral home, the hearse driver noticed Williams had a faint pulse and was barely breathing, but was still alive. There were no hospitals in the area that would serve blacks, even in the case of a medical emergency; the trip to the nearest veterans' hospital was well over a hundred miles. Williams spent more than a month hospitalized recuperating from injuries sustained in the attack.