[2] On June 26, 1915, he was made brigadier general, Iowa National Guard, for service on the Mexican border.

On August 4, 1917 he was promoted to brigadier general (National Army) and given command of the 67th Infantry Brigade, 34th Division, at Camp Cody, in New Mexico.

After returning to the United States, he served as a senior instructor to the Oregon National Guard until his retirement on September 30, 1935.

[2] Allen belonged to the United Spanish War Veterans, the Knights of Pythias, the Masons, and was a Republican.

[1] His papers are held by Lewis & Clark College Aubrey Watzek Library Archives & Special Collections, Portland, Oregon.