HISTORY

Third Line

In a combat formation, most US regiments formed into two firing lines (although some regiments used three.) Almost all regiments had a third non-firing line. This third line consisted of junior officers and sergeants. These "file closers" were intended to keep order in the ranks (prevent troops from breaking and running during combat) and to close gaps in the line when casualties were taken.

In the case of a third firing line, lines two and three stood as normal, while the first line fired and loaded from a kneeling position. Three line firing was rare in combat because a three line formation took more casualties from artillery fire than a two line formation.