 He graduated from the Western Military Academy in 1915 and attended the University of Chicago before leaving in 1917 to join the United States Army, after the American entry into World War I.

Collins completed the course at the Officer Training Camp in Little Rock, Arkansas, in 1917, received his commission as a second lieutenant in the Infantry Branch, and was assigned to the 3rd Infantry Regiment.Collins served with the 3rd Infantry on the Mexican Border at Eagle Pass, Texas, at the end of the Pancho Villa Expedition and during World War I.

Collins remained with the 3rd Infantry, including assignments at Camp Sherman, Ohio, and Fort Snelling, Minnesota.In 1922, he was assigned to the 19th Infantry Regiment at Schofield Barracks, Hawaii.