What weapon used during the civil war was much more deadly by world war 1?

The weapon that became much more deadly by World War I compared to its use during the Civil War was the rifle, particularly the bolt-action rifle. During the Civil War, rifles like the Springfield Model 1861 were capable of accurate shooting at long distances, but by World War I, advancements led to more efficient designs, such as the Lee-Enfield and Mauser rifles, which featured higher rates of fire and improved accuracy. Additionally, the introduction of smokeless powder increased the lethality of these weapons, making them far deadlier in combat situations.