The first massive clash of the Civil War took place near a stream known as Bull Run on July 21, 1861. A well-equipped but poorly trained Union army of 35,000 had marched from Washington, where cheering crowds expected them to return victorious. Most of the soldiers were 90-day volunteers who had little knowledge of what war would mean. Instead of an easy march to Richmond, they ran into the Confederate army of Gen. P. G. T. Beauregard and a fierce stand by Rebel Gen. Thomas J. Jackson, who would forever after be known as "Stonewall." The 10 hours of heavy fighting stunned soldiers on both sides, as well as onlookers who had ridden out from Washington to watch. A Confederate victory shattered any hopes that the war would end quickly.

Union and Confederate armies met here again on August 28 through 30, 1862, in the Second Battle of Manassas, which secured Gen. Robert E. Lee's place in history as his 55,000 men soundly defeated the Union army under Gen. John Pope.

Start your tour at the Henry Hill Visitor Center, where a museum, a 45-minute film ($3 admission; shown on the hour 9am-4pm), and a 6-minute battle map program tell the story. These hills are excellent for hiking, and there are a number of self-guided walking tours that highlight Henry Hill, Stone Bridge, and the other critical areas of the two battles. Allow about 2 hours to take in the visitor center and the First Battle walking tour (it's about 1 mile long). The tour of the entire First Battle area is 6 1/2 miles long. The Second Battle of Manassas, which raged over a much larger area, is covered in a self-guided 12-mile driving tour that will take about 1 1/2 hours.