He was posthumously awarded the nation's highest military decoration for valor, the Medal of Honor, for heroic actions "above and beyond the call of duty" on March 3, 1945, during the Battle of Iwo Jima.

In January 1944, Williams received orders to the Fleet Marine Force (FMF), Field Medical School Battalion, Camp Elliott, San Diego, for combat field training, and transferred a few months later to Headquarters, 5th Marine Division at Camp Pendleton, California.

On March 3, when a Marine, James Naughton, was wounded forward of the front lines, Williams went to assist him and was hit by enemy fire.

Heroically completing his task despite pain and profuse bleeding, he then endeavored to make his way to the rear in search of adequate aid for himself when struck down by a Japanese sniper bullet which caused his collapse.

Succumbing later as a result of his self-sacrificing service to others, Williams, by his courageous determination, unwavering fortitude and valiant performance of duty, served as an inspiring example of heroism, in keeping with the highest traditions of the U.S.