Straps and other items.

Straps as rank devices are first mentioned in Army regulations in the 1830's. I believe it evolved from a strap used to help secure the dress epaulettes to the proper place on the shoulder. It seems to have remained in place even when the epaulettes were removed from the uniform. The actual rank insignia appears at both ends of the strap permitting recognition of rank from various angles of view. The color on the field signifies the branch of service, red for artillery. yellow for cavalry, blue for infantry and black for staff.