Hello Shawn,

This flag is a regimental designating flag as set out in General Order No. 102 of 24 March 1862. This system of flags is more commonly known as McClellan’s system of designating flags. The system provided specific flags for the corps, divisions, brigades and regiments of the Army of the Potomac. The first to fourth brigades of the first division of each corps all used red and white flags in different arrangements of vertical and horizontal stripes. The use of a number on the flag in turn specified which regiment (again the first to the fourth) in the brigade the flag belonged to.

Thus the flag Kershaw’s Brigade captured must have belonged to the first regiment of one of the brigades of the first division of an unknown corps.

Ryan Toews