As the day slowly progressed, Major General George B. McClellan's men forced the battered but determined troops on
the right of General Lee's line towards the town of Sharpsburg. After suffering casualties as horrendous as their Union foes, it seemed
as if Major General Burnside, the commander of the Union's left flank, would sweep the Southerners from the field. With only the
Potomac River at their back, disaster awaited the Confederates who would have had no immediate route of retreat. Unknown to General
Burnside, after CSA Major General "Stonewall" Jackson's capture of Harpers Ferry, he had left one Division behind to parole
Union prisoners. Just as it seemed that Lee's men would be pushed back through the town, CSA Major General Ambrose Powell Hill, moving
up the road from Harpers Ferry, slammed into Burnside's hard fought and exhausted men, rolling up the left flank of the Union line.
Although estimates place the Confederate Army of Northern Virginia's overall losses at about 25% of their available men
, A. P. Hill's timely arrival after a 17 mile march, allowed the
Army of Northern Virginia to move on and fight again another day. This picture shows a lone Confederate cannon, positioned just outside
the walls of the Antietam National Cemetery, facing in the direction Burnside's men approached.
The fiery, proud Confederate Major
General Ambrose Powell Hill, who not infrequently came into conflict with his commanding officer, would write proudly in his official
report, "By direction of General Jackson, I remained at Harper's Ferry until the morning of the 17th, when, at 6.30 a.m., I
received an order from General Lee to move to Sharpsburg. Leaving Thomas, with his brigade, to complete the removal of the captured
property, my division was put in motion at 7.30 a.m. The head of my column arrived upon the battle-field of Sharpsburg, a distance of
17 miles, at 2.30 o'clock, and, reporting in person to General Lee, he directed me to take position on our right...My troops were not
in a moment too soon. The enemy had already advanced in three lines, had broken through Jones' division, captured McIntosh's battery,
and were in the full the of success. With a yell of defiance, Archer charged them, retook McIntosh's guns, and drove them back pell
mell. Branch and Gregg, with their old veterans, sternly held their ground, and, pouring in destructive volleys, the tide of the enemy's
urged back, and, breaking in confusion, passed out of sight...The three brigades of my division actively engaged did not number over
2,000 men, and these, with the help of my splendid batteries, drove back Burnside's corps of 15,000 men...My loss was 63 killed, 283
wounded; total, 346."
General Hill's highly successful counterattack, including his own official report, often state that Union soldiers fled precipitously
almost without a fight when the hard marching southerners stormed the field. Surely, some of the greener Union men and those who had
been fighting for hours, did withdraw with less decorum than they may have later preferred. However, without question, others stayed
and fought. In comparison to A. P. Hill's casualties noted above for almost his entire division, the 16th Connecticut Infantry alone
lost 43 men killed and 151 wounded on these blood soaked fields as it was driven back over the ground it had just fought to capture.