How did African American help the war effort in the north?

African Americans helped the war effort in the South in the way that when the war began, over 3.5 million enslaved people lived in the Confederacy. Making up more than 30 percent of the region's population and the bulk of its workforce, enslaved workers labored on plantations and in vital iron, slat, and lead mines. Some worked as nurses in military hospitals and cooks in the army. By the end of the war, about one-sixth of the enslaved population had fled to areas controlled by Union armies.

The possibility of a slave rebellion terrified white Southerners. For this reason most Southerners refused to use African Americans as soldiers - for then they would be given weapons.

Near the end of the war, however, the Confederate military became desperate. Robert E. Lee and some others supported using African Americans as soldiers and believed that those who fought should be freed. He Confederate Congress passed a law in 1865 to enlist enslaved people, although the law did not include automatic freedom. The war ended before any regiments could be organized.