Complex sentence: LeMay was appointed Vice Chief of Staff of the United States Air Force in July 1957, serving until 1961, when he was made the fifth Chief of Staff of the United States Air Force on the retirement of Gen Thomas White.
Split into simpler sentences: LeMay was appointed Vice Chief of Staff of the United States Air Force in July 1957, serving until 1961. Following service as USAF Vice Chief of Staff (1957--1961), LeMay was made the fifth Chief of Staff of the United States Air Force on the retirement of Gen Thomas White.