An important area of development was the way that cartridges were stored and used in the weapon. The Spencer repeating rifle was a breech-loading manually operated lever-action rifle that was adopted by the United States. Over 20,000 were used during the American Civil War. It was the first adoption of a removable magazine-fed infantry rifle. The design was completed by Christopher Spencer in 1860. It used copper rimfire cartridges stored in a removable seven-round tube magazine, enabling the rounds to be fired one after another. When the magazine was empty, it could be exchanged for another.
