Medal of Honor action
His next campaign was at Iwo Jima where he distinguished himself with actions "above and beyond the call of duty" — for which he would be awarded the Medal of Honor. Landing on February 21, 1945, Williams, by then a corporal, distinguished himself two days later when American tanks, trying to open a lane for infantry, encountered a network of reinforced concrete pillboxes, buried mines, and black volcanic sands. Williams went forward alone with his 70-pound (32 kg) flamethrower to attempt the reduction of devastating machine gun fire from the unyielding positions.
Covered by only four riflemen, he fought for four hours under terrific enemy small-arms fire and repeatedly returned to his own lines to prepare demolition charges and obtain serviced flame throwers. He returned to the front, frequently to the rear of hostile emplacements, to wipe out one position after another. At one point, a wisp of smoke alerted him to the air vent of a Japanese bunker, and he approached close enough to put the nozzle of his flamethrower through the hole, killing the occupants. On another occasion, he charged enemy riflemen who attempted to stop him with bayonets and destroyed them with a burst of flame from his weapon.
These actions occurred on the same day as the raising of the U.S. flag on the island's Mount Suribachi, although Williams was not able to witness the event. He fought through the remainder of the five-week-long battle and was wounded on March 6, for which he was awarded the Purple Heart.
In September 1945, he returned to the United States, and on October 1 he joined Marine Corps Headquarters in Washington, D.C. He was presented the Medal of Honor by President Harry S. Truman on October 5, 1945, at the White House.