Battle of Bull Run
This battle was also known as the Battle of Manassas. Jefferson Davis waited for Union troops to travel to Manassas Junction, a major railroad center. Lincoln wrongly assumed that McDowell's 37,000 men could win because they outnumbered the Confederates. The Union had the upper hand until General Joseph Johnston arrived to reinforce rebel troops and put the Union in the defensive. This battle made everyone realize that the war was serious and could not be simply resolved quickly.