In 1939 at the National Horse Show at Madison Square Garden, he won first place in the Individual Military and Police Jumping event.

In 1943, he attended a shortened general staff course at Fort Leavenworth, and after graduation joined the 106th Cavalry Group at Camp Hood, Texas, as a squadron commander, and later as regimental executive officer.

[1] After brief occupation duty in Germany at the end of World War II, Polk returned to the United States and became Chief of Tactics at the Ground General School at Fort Riley, Kansas, and later attended the Armed Forces Staff College.

Following an assignment as Assistant Chief of Staff for Plans and Operations, Land Forces Central Europe, at NATO Headquarters at Fontainebleau under General Dr. Hans Speidel, Polk returned to the U.S. and became Director of the Policy Planning Staff in the Office of the Assistant Secretary of Defense for International Security Affairs.

Polk retired to El Paso, Texas,[4] and served as Chairman of the Board of the U.S. Cavalry Association from 1978 to 1992,[5] and President of Army Emergency Relief from 1975 to 1984.

[6] He died on 18 February 1992, at William Beaumont Army Medical Center in El Paso, Texas after battling cancer and pneumonia.