The Spencer repeating rifle was a major leap forward in infantry firepower, and more than one hundred thousand of them were purchased by the US military during the Civil War. The Spencer offered a 7-round magazine of rimfire .56 caliber cartridges in an era when the single-shot muzzleloading rifle was still predominant. This particular Spencer is a long rifle which was one of roughly 1100 rebuilt from damaged carbines in 1871 at Springfield Arsenal.