A sapper or combat engineer is a combatant soldier who performs a wide variety of combat engineering duties; typically including, but not limited to, bridge-building, demolitions, field defenses, and road repair. Sappers are also trained to serve as infantry when needed in both defensive and offensive operations.
In warfare history, miners dug trenches, moats and tunnels. The terms Sapper and Miner became synonymous as warfare changed.
During the Civil War, Sappers built pontoon and railroad bridges, constructed forts and batteries, demolished enemy supply lines and conducted siege warfare. In December 1862 Union Army engineers laid six pontoon bridges across the Rappahannock River, under devastating fire from Confederate sharpshooters, in support of the Union attack on Fredericksburg, Virginia.