This was the first major land battle of the armies in Virginia. On July 16, 1861, the Union army under Brig. Gen. Irvin McDowell marched from Washington against the Confederate army. Confederates extended and broke the Union right flank. The Federal retreat rapidly deteriorated into a rout. In the movie, both sides marched into the battle and many were killed and they blew up a horse by where they were fighting and Jonas went back after the battle and saw countless bodies dead.