William Thomas Bayless on March 23, 1918, enlisted in the U.S. Marines and for duty was assigned to Company 45, 6th Regiment, later transferred to the 82nd Company. Parris Island, SC, was his training station. Sailed for France in April 1918 and as a member of his unit took part in the fighting at Belleau Wood and Chateau Thierry. Sergeant Bayless was last seen on July 19, 1918 during a battle.
He is memorialized on the Tablets of the Missing at the Aisne-Marne American Cemetery, Belleau, France.