Colonel (United States) Colonel (United States) In the United States Army, Marine Corps, and Air Force, colonel () is the most senior field grade military officer rank, immediately above the rank of lieutenant colonel and immediately below the rank of brigadier general. It is equivalent to the naval rank of captain in the other uniformed services. The pay grade for colonel is O-6. The insignia of the rank of colonel, as seen on the right, is worn on the officer's left side (a mirror-image version is worn on the right side, such that the eagle always faces forward to the wearer's front; the
Lieutenant colonel (United States) 1791, there was only one lieutenant colonel in the US Army (Josiah Harmar), who acted as the army's commanding officer. In the Continental Army aides to the Commander in Chief, viz., Lieutenant General George Washington, were lieutenant colonels. Additionally, certain officers serving under the Adjutant General, Inspector General, and Judge Advocate General, ranked as lieutenant colonels. During the 19th century, lieutenant colonel was often a terminal rank for many officers, since the rank of "full colonel" was considered extremely prestigious reserved only for the most successful officers. Upon the outbreak of the Civil War, the rank of lieutenant colonel became