The Battle of Antietam took place on Sept. 17, 1862. The first major battle fought on Northern soil, the Battle of Antietam was the bloodiest day in U.S. history, causing more than 22,000 casualties.
The Maryland Campaign was Confederate General Robert E. Lee's plan to bring the war into the North and give some respite to the states of the South, which had been hit hard by Union attacks. The Northern army under General George McClellan was ready for the Confederates, meeting them at Antietam Creek near Sharpsburg, Md. Though the Northern soldiers were unable to use their numerical superiority to crush the Southern troops, they did check the Confederates' advance. The Union success in halting Lee's march north gave President Lincoln the political cover he needed to issue to Emancipation Proclamation on Sept. 22, 1862.