Pop Quiz: Most Deadly Battle on U.S. Soil?

Look at you! You chose correctly!

The battle, known as both the Battle of Antietam (by the Union after the nearby creek),
and the Battle of Sharpsburg (by the Confederates after the nearest town or railroad junction),
would lead to combined cumulative casualty rates for both sides of over 22,000
and be seen as the bloodiest battle not only of the Civil War, but also the bloodiest battle on American soil.