How was the battle of antietam a crucial victory for the union

It allowed the Union to repel the Confederate invasion of the North.

"a shortage of traditional labor created new opportunities in the workplace. a major cause of the internment of japanese americans during world war ii was. racial prejudice. in the early 1940's, the "destroyers-for-military-bases deal" with great britain and the lend-lease act were evidence that the united states."

the answer is a. harriet tubman was a nurse on the battlefield.