Nicknamed "Pee Wee" because of his diminutive 5 ft 2 in (1.57 m) stature, Collier was born in Uvalde, Texas on September 8, 1898.

[4] Collier served in assignments throughout the United States, including instructor at New Mexico Military Institute and postings to Ft. Riley, Kansas, Ft. Benning, Georgia, and the Philippines.

[7] After graduating from the Command and General Staff College in 1941, Collier was assigned to the 2nd Armored Division for World War II.

[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.

[28][29][30] At the end of World War II, the Union of Soviet Socialist Republics decorated him with the Order of Alexander Nevsky as the 2nd Armored Division linked up with elements of the Red Army.