Shoulder Straps of the pre-Civil War period 1830s-1851 used a bimetallic system as a branch and grade indication. They always have a dark blue field as branch colors were not used until 1851. Compared with shoulder straps dating after 1851 they seem very long and narrow.
This strap has silver bullion embroidered bars and border, but color can be hard to appreciate because old bullion will tarnish. It has quarter-inch all dead bullion embroidered border. The field is dark blue velvet. The back is not finished off in any way.
The oddest feature of the bimetallic era shoulder strap is the manner that grades were designated. This is as follows:
|First Lieutenant||Silver||One Gold Bar at either end|
|Captain||Silver||Two Gold Bars at either end|
|Major||Silver||Gold Leaf at either end|
|Lieutenant Colonel||Silver||Silver Leaf at either end|
|First Lieutenant||Gold||One Silver Bar at either end|
|Captain||Gold||Two Silver Bars at either end|
|Major||Gold||Silver Leaf at either end|
|Lieutenant Colonel||Gold||Gold Leaf at either end|
|Brigadier General||Gold||One Silver Star|
|Major General||Gold||Two Silver Stars|
|Major General Commanding||Gold||Three Silver Stars|
The important feature was the color of the border, which indicated the branch. The color of the device was secondary and in the main contrasted with the color of the border. Thus, a colonel's eagle might be either gold or silver, a lieutenant colonel's and major's leaf either gold or silver and the bars of company officers either gold or silver.
In 1851 new regulations changed all this and branch colors became a major feature of the American uniforms, both for officers and enlisted men.