Rifled musket
The rifled musket is a long-barreled infantry weapon (to be distinguished from the shorter "rifle" carried by some light infantry units), usually percussion, that was common in the 19th century. Rifling gave the rifled musket better long-range accuracy than its smoothbore predecessors.
Use in the United States
The first rifled musket to be adopted by the United States was the Model 1855. It was followed by the Model 1861, the most common shoulder weapon of the Civil War. In addition, many older, smoothbore muskets were rifled in the years prior to and during the Civil War. The muzzle-loading rifled musket was eventually succeeded by the Model 1865 breechloading rifle, essentially a breechloading conversion of the Model 1863. This would evolve, through several models, into the famous Model 1873 "trapdoor".