eleven o'clock at night
Overwhelmed by vastly superior numbers , many of the Confederates had left their posts , and Breckenridge was in vain trying to rally them when Gracie 's brigade came up . The position was reoccupied and the battle continued . At noon Burnside with his corps arrived and joined the assailants ; while Butler , discovering at last that the troops in front of him were withdrawn , moved out and barred the road against re-enforcements from Richmond . Nevertheless , the Confederates held their ground all the afternoon and until eleven o'clock at night , when the assault ceased . At midnight Beauregard withdrew his troops from the defenses that they were too few to hold , and set them to work to throw up fresh intrenchments on a shorter line behind . All night the men worked with their bayonets , canteens , and any tools that came to hand . It was well for them that the enemy were so exhausted that it was noon before they were ready to advance again , for by this time help was at hand .