[2]: 17  Having claimed an 1896 date of birth in order to meet the minimum age for a commission, In May 1917 Williams began the officers training course at Camp Bullis, Leon Springs, Texas.

[2]: 22, 26  He received his commission in August 1917, four months after the American entry into World War I, and was appointed a second lieutenant in the Infantry Branch of the Officer Reserve Corps.

[12] The Japanese attack on Pearl Harbor and the subsequent German declaration of war against the United States in December 1941 officially brought the country into World War II, and, by 1943, Williams was the commanding officer (CO) of the 378th Infantry Regiment, part of the 95th Infantry Division,[13] after having been promoted to the rank of colonel in the Army of the United States (AUS) on August 7, 1942.

[14] Williams was a member of the court-martial, and growing annoyed with the drawn-out proceedings, suggested that the trial ought to be ended quickly, since the defendant's guilt was not in doubt and he deserved execution by hanging.

[12] Reactivated for World War II, the 90th Division took part in Operation Overlord, the Allied invasion of Northern France, in June 1944.

[16] While en route to their landing site, Williams and numerous 90th Division soldiers were on board the transport ship Susan B. Anthony when it struck a mine.

[18] Shortly after the 90th Infantry Division began its part in the Normandy invasion, Major General J. Lawton Collins, the VII Corps commander, decided that the unit was not performing satisfactorily in combat.

[22][23] From 1952 to 1953, Williams commanded the 25th Infantry Division in the Korean War, earning the Distinguished Service Cross and Silver Star and receiving promotion to the two-star rank of major general.

[28][29] From January to September 1955, he commanded the Fourth Army at Fort Sam Houston, Texas, receiving promotion to the three-star rank of lieutenant general.

He received two waivers to serve in Vietnam past his mandatory retirement date as the result of the positive relationship he had fostered with South Vietnamese authorities, who requested to continue working with him.

Major General Williams distinguished himself by extraordinary heroism in action against enemy aggressor forces in the vicinity of Chu-Dong, Korea, on the morning of 15 July 1953.

On that date, General Williams was advised of a large-scale enemy attack consisting of six hostile divisions and extending the width of the corps front.

Dipping repeatedly to within a few feet of the hostile positions, General Williams noted the disposition of the foe without regard for the heavy fire directed against his craft.

Only then did he return to his command post to plan and coordinate a counter operation which substantially reduced the fighting potential of the hostile force through the tremendous casualties they suffered.