Attached is an image of a scarce belt that sometimes goes unnoticed. Shortly after adopting the Roman style short sword for artillery, the army also adopted them for use by infantry sergeants. The difference in the two belts being the motif on one of the discs supporting the S-shaped clasp. The artillery belts had crossed cannons with a US; the infantry had stacked muskets. We tend to refer to them as NCO belts and swords, but they seem to have been restricted to sergeants only, not corporals.
The material is white buff leather, with a frog on the left and an adjusting buckle on right.
The disc pattern was changed in 1834 to a generic US and the belt itself was phased out starting in 1839 with the adoption of the 1840 pattern NCO sword (which, like this, was restricted to sergeants,) carried on a shoulder sling.
Robert Dingee supplied a lot of the belts and brass to the army. The disc pattern on this, however, does not match Dingee's and is thought to be either a version made for one of the states or a federal product from Allegany Arsenal.
See Campbell and O'Donnell for details on the plates.