In both the Continental and British Armies of the Revolutionary War, Lieutenant Colonels were considered the regiment’s second in command—but at the start of the war this meant two different things in actual practice. According to the highly respected reference work
The Continental Army by military historian Robert K. Wright, Jr., Colonels were indeed designated as commanding officers of British regiments, but it was actually a titular rank: they dealt only with financial issues and left the actual command and control of the unit up to the Lieutenant Commander and Major. In the Continental Army, on the other hand, regiments were assigned three (sometimes four) field officers—a Colonel, Lieutenant Colonel, and a Major (or two)—and Colonels actually commanded the troops.
As the war progressed, the Continental Army and Congress began to realize that the discrepancy between the two systems made prisoner exchanges—a common practice of warfare at the time—more difficult that necessary because while the British might hold American Colonels as POWs, the British Colonels were not combat officers and therefore were almost never captured—and thus never available to be used for the exchange.
More Army Lieutenant Colonel InsigniasIn 1778, Congress decided to take steps to address this by mandating that each regiment was to eliminate its Colonel through attrition—i.e., not replace them when captured, wounded, or killed—and place command in the hands of to the Lieutenant Colonel, with a Major serving as a subordinate.
This formula was never achieved in all the Army’s regiments. In those cases where Lieutenant Colonels were serving as the senior officers, their title was expanded to the more descriptive Lieutenant Colonel Commandant.