The Model 1861, with all of its variants, was the most commonly used longarm in the American Civil War, with over 700,000 manufactured.

It also featured a new ramrod, a case-hardened lock, a new hammer, and a redesigned bolster (percussion chamber).

By the end of the Civil War, muzzle-loading rifles and muskets were considered obsolete.

In the years following the Civil War, many Model 1863 muskets were converted into breech-loading "Trapdoor Springfields".

The conversion of Model 1863 rifles therefore represented a significant cost savings to the U.S. military.