On July 21, 1861, the First Battle of Bull Run was fought just 30 miles from Washington, D.C. See how much you know about this major Civil War battle with these five surprising facts about the First Battle of Bull Run…

The Battle of Bull Run Was Where Stonewall Jackson Earned His Nickname. General Thomas Jackson, leading his troop of Virginia volunteers in the battle on July 21, began a major push forward to block a gap in the Confederate line from Union attack. One of the other Confederate generals engaged in the battle remarked that Jackson was standing in place like a stone wall. The nickname stuck, and Jackson was promoted to major general that October.

Around 55,000 Union and Confederate Troops Fought in the Battle. The Union Army of Northeastern Virginia, commanded by Brig. Gen. Irvin McDowell was composed of about 35,000 troops, while the Confederate troops that were called the Army of the Potomac and under Brig. Gen. P.G.T. Beauregard had about 20,000 troops. The Union suffered 2,708 casualties—481 soldiers were killed, 1,011 were wounded and 1,216 were listed as missing. The Confederates are estimated to have suffered 1,982 casualties, which included 387 fatalities, 1,582 wounded and 13 reported missing.

The Fight Was Also Called the Battle of Manassas. Confederates named battles after the cities or towns that were nearby. The Federal government named them after nearby rivers or creeks. For this reason, the Confederates referred to this confrontation as the Battle of Manassas, and the Union called it Bull Run. which is a river tributary of the Occoquan River.

It Was the First Time a Railroad Was Used to Move Troops General Beauregard wanted reinforcements to increase the Confederate's chance of success in the upcoming battle; however, rebel General Joseph Johnston and his 12,000 troops were in the Shenandoah Valley, some distance away. To get there, Johnston marched his troops to Piedmont Station where they boarded the Manassas Gap Railroad, which took them to the battlefield.

The Was Some Uniform Confusion Some Southern soldiers at Bull Run wore blue uniforms instead of Confederate gray, and some Northern soldiers wore gray instead of Union blue. They had to fight in their state militia uniforms because neither side had enough official uniforms.  The lack of uniforms led to confusion on the battlefield, and soldiers often shot people from their own side.