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
United States Army officer rank insignia had silver eagles on gold epaulettes. No insignia existed yet for lieutenant colonels, majors, captains, and lieutenants—the length and size of the fringe showing the difference of grade. In 1836, shoulder straps were adopted to replace the epaulette for field duty. The straps followed the same color combination as the epaulettes; that is, the border was gold with silver insignia for all officers except those of infantry which had silver border with gold insignia. At that time, lieutenant colonels and majors were authorized leaves, captains were authorized two bars, and first lieutenants were authorized one bar on the shoulder straps.