What were the positive outcomes of the Battle of Antietam for the Union?

Answer: The outcome of the battle. The Union won the Battle of Antietam. They defeated the Confederate forces, nd crushed Lee's forces. In total, about 22,000 troops from both sides lay dead. Even though this battle was a costly one, it gave Lincoln the confidence to issue the Emancipation Proclamation which freed all slaves.

Ik I'm late but it's a and c

Explanation:

A. It slowed Confederate momentum.

C. It meant that Britain did not recognize the Confederacy as a free state