During World War I, Adelaido served with Company E of the 158th Infantry Regiment, 40th Division.
When the 1st Arizona Volunteer Infantry was drafted into federal service on 5 Aug 1917, it was re-designated as the 158th Infantry Regiment as part of the 79th Brigade, 40th Division. The Division was sent overseas to France in August 1918. The regiment saw no active service at the front, however its men furnished replacement personnel to other units. The regiment was honored by acting as Guard of Honor to President Woodrow Wilson during his visit in France in 1918.
Inscription: PVT US ARMY CO E 158 INF 40 DIVISION WORLD WAR I