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 stars for general officers, worn on epaulettes. From 1821 to 1832, the Army used chevrons to identify officer grades, a practice that is still observed at West Point for cadet officers. In 1832, epaulettes were specified for all officers, and colonels began wearing the familiar eagle insignia. The epaulettes worn by the infantry were silver, while all other branches had gold epaulettes. In order that the rank insignia would be clearly discernible, they were of the opposite color; that is, the infantry colonels had an eagle of gold because it was placed on a silver epaulette and all other colonels