The M1861 Springfield is a muzzle-loading rifle that was widely used during the American Civil War. It is a .58 caliber rifle, known for its accuracy and range, making it a favored weapon among Union soldiers. The rifle features a rifled barrel, which improves projectile stability and accuracy over longer distances. Designed by Eli Whitney and produced at the Springfield Armory, the M1861 Springfield became the standard infantry weapon for the Union Army. Its simple design and reliability contributed to its popularity, and it remained in service even after the Civil War, influencing future military rifle designs.