McCain's awards and decorations included the
Army Distinguished Service Medal for his First World War service, and a second award of the DSM to recognize his World War II accomplishments.
First Distinguished Service Medal citation The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Lieutenant Colonel (Field Artillery) William Alexander McCain, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I. As Ordnance Officer of the 5th Army Corps, Colonel McCain displayed superior judgment, exceptional ability, and zealous devotion to duty, and executed successfully the difficult problems of the supply of munitions, thereby contributing materially to the success of the operations of the 5th Army Corps, and rendering important services to the American Expeditionary Forces, in the operations against the enemy during the St. Mihiel and Meuse-Argonne offensives.
Service: United States Army
Rank: Lieutenant Colonel (Field Artillery)
Division: 5th Army Corps, American Expeditionary Forces
Action Date: World War I
Orders: War Department, General Orders No. 12 (1929) ==Dates of rank==