Uniform of the Union Army letters US. Officers, NCOs and cavalry troopers were equipped with a sword belt with a rectangular buckle with eagle motif. Rank was displayed on epaulettes (dress occasions) or shoulder straps(field duties): no insignia for a second lieutenant, one gold bar for a first lieutenant, two gold bars for a captain, a gold oak leaf for a major, a silver oak leaf for a lieutenant colonel, a silver eagle for a colonel and one, two or three silver stars for a general, depending on his seniority. The color of the shoulder strap fields – with trims in gold braid – were
Uniform of the Union Army as follows: Contemporary photographs and a Winslow Homer painting, "Playing Old Soldier", show staff officers occasionally added their departmental initials within the shoulder straps between the rank insignia. "M.S." for "Medical Staff" appears to have been the most common. With the exception of slight changes to the representing insignia for the more junior commissioned grades as well as additional color combinations for new career fields, the shoulder strap insignia and color scheme survives largely unchanged in the modern era on the Army Service Uniform. Individual officers would sometimes add gold braid Austrian knots on their sleeves but this practice was