Collier attended the United States Military Academy, from which he graduated in 1918. After receiving his commission, Collier was assigned to Europe to carry out an observation tour of World War I battlefields.[3]
Assigned to the Cavalry branch, Collier completed the Cavalry Officer Basic Course in 1920.[4]
After serving as the Chief of Armor, Collier assumed command of I Corps in Korea on July 13, 1954.[17] In November he was assigned additional duty as interim deputy commander of the Eighth United States Army until the arrival of the permanent deputy commander, Lt. Gen. Claude B. Ferenbaugh, in early January 1955.[18][19] Ferenbaugh retired at the end of June and Collier relinquished command of I Corps to become deputy commander of Eighth Army and U.S. Army Forces Far East.[20] He promptly made nationwide headlines when he attempted to prevent U.S. service members from fraternizing with South Korean women, an effort that proved unsuccessful when commanders in areas outside Eighth Army control did not follow Collier's example.[21][22][23][24]
Post Korean War
Collier returned to the United States in 1955 to assume command of the Fourth United States Army, where he served until his 1958 retirement.[25][26][27]
^Iron Knights: the United States 66th Armored Regiment, 1918–1945, by Gordon A. Blaker, 1999, page 162
^A Time for Trumpets: The Untold Story of the Battle of the Bulge, by Charles B. MacDonald, 1997, page 567
^In the Middle of the Fight: an Assessment of Medium-Armored Forces in Past Military Operations, by David E. Johnson, Adam Grissom, and Olga Oliker, published by Rand Corporation 2008, page 197
^Online database, U.S. Veterans Gravesites, ca.1775-2006
^Empric, Bruce E. (2024), Uncommon Allies: U.S. Army Recipients of Soviet Military Decorations in World War II, Teufelsberg Press, p. 86, ISBN979-8-3444-6807-5
^Newspaper editorial, Gen. Collier, San Antonio Light, July 10, 1958