My grandfather Clarence Arthur (Casey) Robertson was drafted into World War I in June 1917. He was 23. He shipped out to Europe with Co. E 166 Infantry in October 1917, fought in 3 major and 3 minor battle operations and returned after serving in the Army of Occupation in April 1919.
Here he is in a picture taken in France. Back row, left to right: Casey Robertson, Floyd Hiser, Henry Green, Willard Rogers. Front row, left to right: Fay Wolford, an unknown Frenchman, Buck Horshfield. Armistice Day was November 11, 1918.
The War to End All Wars, did not.