In August 1862, the regiment fell under the control of General John Pope. At the Second Battle of Bull Run (also known as the Second Battle of Manassas), the 5th New York Volunteer Infantry regiment was forced to withstand the advancing forces of General James Longstreet. In underestimating the size of the Confederate army, Pope ordered the regiment to support Hazlett’s Battery. Longstreet’s soldiers easily outnumbered the small regiment, and the Texas Brigade quickly inflicted over 330 casualties in the regiment. One hundred twenty Zouaves were killed within eight minutes, the greatest single battle fatality of all Federal volunteer infantry regiments in the entire Civil War. The entire Color Guard was killed, except for one man. The only officer to survive the battle was Captain Cleveland Winslow.