 The 5th was part of Major General Joseph Mansfield's XII Corps and Lt. Col. Hector Tyndale's Brigade, along with the 7th Ohio Infantry, 66th Ohio Infantry, and 28th Pennsylvania Infantry.Entering the battle in support of Joseph Hooker's I Corps, Tyndale's brigade inflicted heavy casualties on Alfred H. Colquitt's brigade and helped drive the Confederates out of the Cornfield.Pushing the Confederates south to the Dunker Church, Tyndale's men held the area until the afternoon when lack of support, heavy losses and low ammunition compelled them to retreat.