Colonel T. G. Morehead, who commanded the 106th Pennsylvania, of the Second Corps. At 7.20 A. M. the order came to advance, and with a cheer the Second Corps--men who for over two years had never lost a gun nor struck a color — pressed forward. But again they were halted. It was almost an hour later when Sedgwick's division, with Sumner at the head, crossed the Antietam. Arriving nearly opposite the Dunker church, it swept out over the cornfields. On it went, by Greene's right, through the West Woods; here it met the awful counter-stroke of Early's reinforced division and, stubbornly resisting, was hurled back with frightful loss. Early in the morning of September 17, 1862, Knap's battery (shown below) got into the thick of the action of Antietam. General Mansfield had posted it opposite the north end of the West Woods, close to the Confederate line. The guns opened fire at seven o'clock. Practically unsupported, the battery was twice charged upon during the morning; but quickly substituting canister for shot and shell, the men held their ground and stemmed the Confederate advance. Near this spot General Mansfield was mortally wounded while deploying his troops. About noon a section of Knap's battery was detached to the assistance of General Greene, in the East Woods.