[2][3] Hickey worked at a Memphis, Tennessee, lumber company until deciding to enlist for World War I.

[2][3] He joined the Army, attended Officer Candidate School at Leon Springs, Texas, and in 1917 was commissioned as a second lieutenant in the Artillery.

[2][3] In the early 1930s, he served with the 7th Field Artillery Regiment at Madison Barracks, New York, afterwards being assigned to duty as Director of the United States Park Police in Washington, D.C. From 1938 to 1940, he served in the Philippines, and from 1940 to 1941 he commanded the 9th Infantry Regiment at Fort Bragg, North Carolina.

After World War II, the division carried out occupation duty near Langen, and was inactivated in November 1945.

[4] He served under MacArthur's successors, Matthew Ridgway and Mark Clark, and played an important role in the planning and execution of operations during the Korean War.