Brig. Gen. W. N. Pendleton, Lee’s chief of artillery. From Miller’s Photographic History of the Civil War.
Brig. Gen. Henry Hunt, McClellan’s chief of artillery.
The Lines Are Poised for Action
At 2 p.m. on the 16th, Hooker marched from his camp near Keedysville, crossed the Upper Bridge, and late in the afternoon reached the Hagerstown Pike. Under cover of the North Woods, his divisions formed for the attack on both sides of the pike. A massed force of more than 12,000 men was ready to advance on the Confederates.
Union artillery in battery line. From 1863 photograph. Courtesy, Library of Congress.
Lee’s thin line, 3 miles long, had been reinforced early on the 16th by the arrival of Jackson’s troops from Harpers Ferry. They were placed where they could support the northern part of the Confederate line. John Walker’s division, arriving from Harpers Ferry in the afternoon, took position south of Sharpsburg.
Jackson now commanded the Confederate front north of Sharpsburg; Longstreet, with a part of his force north of the village, extended the line nearly a mile south.
When Lee’s outposts near Antietam Creek informed him in midafternoon that Hooker’s Federals were massing north of Sharpsburg, Lee moved some of his men to advance positions. Hood established a line east of the Hagerstown Pike, with part of his troops in a cornfield and others extending the front to the East Woods. Skirmishers spread out far in front. Additional troops were rushed from reserve near Lee’s headquarters at the Oak Grove west of Sharpsburg; they extended the line west across the Hagerstown Pike.