What is Main Idea #1 of the Battle of Antietam?

Known as "Antietam," the conflict was the worst one-day engagement in American military history and demonstrated that the Union army could compete with the Confederates in the Eastern theater of operations. The preliminary Emancipation Proclamation was issued in a time of strength rather than despair, which enabled President Abraham Lincoln the confidence to release it.

Explanation:

e imma say squidward tentacles

impeachment is when a president is committing treason or doing shading acts while in presidendcy therfor he can be impeached   by congress