William Leon Carey Jr., was born in 1922 to William and Ida Harple Carey in West Chester, Pennsylvania. His father was a World War I veteran and worked as a fireman, feeding coal into steam locomotives for the Pennsylvania Railroad. The family moved to Phoenixville in 1923. William Jr. was one of four children and the only son.
William graduated in 1940 and obtained employment with Phoenixville Iron Company, and later as a plumber. He was a member of the First Methodist Church. William married Florence Smiley of Kimberton.
William entered the Army on October 15, 1942, and received training at Camp Shelby, Mississippi, as part of the newly activated 85th Custer Division. He then received advanced training at Shreveport, Louisiana, Camp Pilot Knob, and Camp Cooks Comb, both in California, and Fort Dix, New Jersey.