Lieutenant colonels are commissioned officers in the U.S. Army, Air Force and Marine Corps. In the field they command medium-sized forces, and can also serve as staff officers in larger units.
A lieutenant colonel ranks above a major and below a full colonel in the order of commissioned ranks in the U.S. armed forces.
In the 19th Century, the U.S. Army was smaller than it is today, and lieutenant colonels were usually of the highest rank, although there were a few exceptions.
A lieutenant colonel generally commands battalions of roughly 300-1,000 troops in the Army and Marine Corps, and squadrons of aircraft in the Air Force.
In larger units such as brigades and divisions, a lieutenant colonel may serve on the staff of a general, offering advice and managing certain operations as needed.
Famous Lieutenant Colonels
Early American political figure Aaron Burr attained the rank of lieutenant colonel, as did cavalry commander George Custer and, more recently, Oliver North.