2. Battle of Antietam
Robert E. Lee led the Army of Northern Virginia into Maryland in September 1862. Lee’s intentions were to foment a revolt in Maryland and inflict a major defeat on Union forces.
Unluckily for Lee, details related to his battle disposition reached Gen. George McClellan, who decided to intercept with the considerably larger Army of the Potomac. But that’s not all. President Abraham Lincoln saw this as a chance to either devastate or badly harm Lee’s army.
All events led to the Battle of Antietam, one in which 22,000 people died making it the bloodiest day in US military history. Despite large numbers, a good understanding of Lee’s dispositions, and a strategic advantage, McClellan was unable to inflict a significant defeat on the Confederates.
Antietam wasn’t a complete failure. The Army of Northern Virginia troops were injured, and McClellan pushed Lee out of Maryland. Following the battle, Lincoln felt confident enough to issue the Emancipation Proclamation.