When the sun rose on July third, the Union troops were ready. They watched as the Confederate troops set up their cannon.

General Beauregard received early warning from Confederate spies that McDowell would attack. Much of his information came from a woman, Missus Rose o 'neal Greenhow.

Union soldiers rose up from behind stone walls and fallen trees. They poured even more gunfire into the Confederate line. More and more bodies fell to the ground. Still, the line moved forward.