Abraham Lincoln vs George McClellan
Lincoln argued that the war must be won, the slaves be freed, and the Union be preserved at all costs. McClellan argued that the war must be gone so that the South could secede, which meant that slavery would continue in the Southern states.

The Confederates forced a retreat on the Union. This would be a long war and showed that the North needed a well-trained army.
General McClellan takes command and builds an army.

The southern Tennessee Union won, but suffered heavy losses, as in
20,000 troops killed or wounded (on both sides).

General Lee wanted the South to invade the North to get Britain's attention. General McClellan leads the Union army into THE bloodiest battle in American history. About 6,000 men died and about 16,000 were wounded. The Union was victorious.

This battle secured eastern Tennessee, which was led by General Grant. It created a major railroad junction, and cleared the way for an invasion on Georgia.

This event allowed the Union to recruit black soldiers. Nearly 180,000 black men joined.

This put the Confederacy on the defensive and set the stage for its surrender. It cut off the Mississippi River and cut the South in half.

The Confederate army of Northern Virginia was defeated. General Lee retreated back into Virginia. In the Union, the victories at Gettysburg and Vicksburg increased the morale of the United States and its armies. Many people now felt that the war could be won. The Confederacy had losses at Vicksburg and Gettysburg, which decreased their morale. They'd be fighting a defensive war.

Lincoln needed to pass the 13th amendment, banning slavery in the United States. The Thirteenth Amendment was passed on January 31, 1865.

The Confederates had defenses at this supply station, and Union army was forced to get in. The Union and Confederate armies fought a series of trench-warfare battles, which were appetizers to WWI.