American Civil War: At the order of President Abraham Lincoln, Union troops begin a 25-mile march into Virginia for what will become the First Battle of Bull Run, the first major land battle of the war.

The American Civil War was a civil war in the United States between the Union and the Confederacy, which was formed in 1861 by states that had seceded from the Union. The central conflict leading to war was a dispute over whether slavery should be permitted to expand into the western territories, leading to more slave states, or be prohibited from doing so, which many believed would place slavery on a course of ultimate extinction.

Abraham Lincoln was the 16th president of the United States, serving from 1861 until his assassination in 1865. He led the United States through the American Civil War, defeating the Confederate States of America and playing a major role in the abolition of slavery.

The Bull Run campaign, also known as the Manassas campaign, was a series of military engagements in the Eastern Theater of the American Civil War in 1861.

Virginia, officially the Commonwealth of Virginia, is a state in the Southeastern and Mid-Atlantic regions of the United States between the Atlantic Coast and the Appalachian Mountains. The state's capital is Richmond and its most populous city is Virginia Beach. Its most populous subdivision is Fairfax County, part of Northern Virginia, where slightly over a third of Virginia's population of more than 8.8 million live.

The First Battle of Bull Run, called the Battle of First Manassas by Confederate forces, was the first major battle of the American Civil War. The battle was fought on July 21, 1861, in Prince William County, Virginia, just north of what is now the city of Manassas and about thirty miles west-southwest of Washington, D.C. The Union Army was slow in positioning themselves, allowing Confederate reinforcements time to arrive by rail. Each side had about 18,000 poorly trained and poorly led troops. The battle was a Confederate victory and was followed by a disorganized post-battle retreat of the Union forces.