when was the rank of chief petty officer established
Chief petty officer (United States) Chief Petty Officer (CPO) is the seventh enlisted rate (E-7) in the United States Navy and U.S. Coast Guard, just above petty officer first class and below senior chief petty officer. The rate of chief petty officer is that of a senior non-commissioned officer, and was established on 1 April 1893 for the United States Navy.[1] The United States Congress first authorized the Coast Guard to use the promotion to chief petty officer on 18 May 1920.[2] Chief petty officer is also the final cadet rate in the U.S. Naval Sea Cadet Corps.
Chief master sergeant Chief Master Sergeant (CMSgt) is the ninth, and highest, enlisted rank in the U.S. Air Force, just above Senior Master Sergeant, and is a senior non-commissioned officer rank. The official term is "Chief Master Sergeant" or "Chief".