Second Manassas | Longstreet's Assault | Aug 30, 1862 | 3:45 to 4:30 p.m.

In the aftermath of Fitz John Porter's failed attack against Jackson on August 30, the Union V Corps was in disarray. Making matters worse, Federal commander John Pope was still unaware that a fresh body of 28,000 Confederates under James Longstreet had arrived on the field and were poised to deliver a crushing blow to the disorganized Union left. In the largest simultaneous mass assault of the war, Longstreet's brigades crushed the Union left flank. First to collapse was the undersized brigade of the 5^th and 10^th New York Infantry regiments commanded by Col. Gouverneur K. Warren. In 15 minutes, both regiments lost over 400 men.