Looking back in time, it may seem today like the ultimate outcome of the American Civil War was a foregone conclusion, but in the summer of 1862, that was anything but the case.

While the year began with a series of Union successes, including the fall of New Orleans, the military fortune of the Confederacy was aggressively reversed by the maneuvers of Robert E. Lee as commanding general of the rebel army, particularly at the Second Battle of Bull Run, where the courage of other rebel icons like Stonewall Jackson helped drive the Union forces on Aug. 30, 1862, all the way to the defenses of the national capital itself.


Pennsylvanians were in panic at the prospect of an invasion by the South, and northern newspapers favorably announced terms of a proposed lasting peace treaty, dividing the union between northern and southern states. Great Britain and France were on the verge of recognizing the Confederate States of America as an independent sovereign, separate from the northern United States.

Lee realized that a decisive victory in the north would very likely have a significant impact on the congressional elections in the fall of 1862, resulting in adoption of Confederate peace terms and an end to the war.

This was the context in which Lee and his army of some 50,000 seasoned soldiers crossed the Potomac into Maryland during the first week of September 1862.

As they marched first to Frederick, they expected to be welcomed as a liberating force. After all, the initial casualties of the Civil War began in Baltimore when a large mob rioted to block the transit of Massachusetts infantrymen to South Carolina to quell the rebellion there.

Maryland was a slave state which had not seceded with its sister southern states only because of federal occupation, including Lincoln's imprisonment of state elected officials and suspension of the writ of habeas corpus.

It surprised the rebels therefore that the Confederate army was greeted with somewhat less than red carpet treatment. Many Marylanders supported the southern cause and despised President Lincoln, but a lot of able-bodied men holding those sympathies had already fled to Virginia to enlist in volunteer units assembled there. Lee had no grand parade of troops behind a marching band. His Army was exhausted, filthy, ill-equipped and surrounded by stench. Much of his infantry was shoeless. Most Marylanders stayed out of sight of the rag-tag marauders, and merchants who overtly displayed favor soon found their stocks depleted in exchange for Confederate scrip of questionable value.

After resting briefly, on Sept. 9, 1862, Lee issued Special Order 191, by which he split the rebel army, dispatching Stonewall Jackson to take the bulk of the troops west to capture Harper's Ferry before marching north to rejoin Lee and the rest of the Confederates, who would proceed directly to Hagerstown, only a short distance from the Mason-Dixon line and the promise of Pennsylvania. Miraculously, on Sept. 13, a misplaced copy of that order came into the hands of the Union commander, General George B. McClellan. It had been used as a wrapper to protect a couple of cigars that were accidentally left at a rebel position a couple of days earlier.

Realizing the opportunity of attacking a divided opponent, McClellan ordered Union forces to secure the three mountain passes between Frederick and Hagerstown. There, on Sept. 14, at the Battle of South Mountain, vastly outnumbered rebels gave way to the arriving federals, but only after delaying the approach of McClellan's army by a precious day, allowing Lee to retreat west to Antietam Creek, where he ordered his troops to dig in to defensive positions.

It was there on Hagerstown Pike at the south end of "the Cornfield" just north of Sharpsburg and along "the Sunken Road" east of town that Lee's fractured army would make its stand, the Potomac River to its back and forward facing more than 75,000 union troops. These places would soon join American military lexicon as hallowed grounds of devastating losses as the mist rose from Antietam Creek at daybreak on Sept. 17, 1862.

That day would soon become the bloodiest day in American history, a record which remains unsurpassed today, 150 years later.