Despite the confusion that gripped the Army of the Potomac during its August 1862 withdrawal from the outskirts of Richmond, one thing remained clear.
So critical a role did the deep-water port at Yorktown play in Maj. Gen. George B. McClellan's failed Peninsula Campaign that — even after retreating down the James River to Fort Monroe — he issued repeated commands urging that the run-down bastion be rebuilt and defended.
"Push the work laid out by the engineer officers with the utmost rapidity," McClellan ordered on Aug. 22, while waiting to depart from Old Point Comfort.
"It is a matter of vital importance that the (work) details be furnished and the work done in the shortest possible time," he added later that day.
"It is imperatively necessary that the work required should be pushed forward with the utmost vigor."
What the Union got when the soldiers of the 4th Corps finished was a strong forward outpost that repeatedly confirmed McClellan's vision.
Fort Yorktown not only provided a crucial harbor for the Federal blockade of the York River and the Chesapeake Bay but also a springboard for expeditions to the Middle Peninsula and Richmond.
It also became a vital magnet and refuge for thousands of runaway slaves, depriving the Confederacy of badly needed food supplies and labor.
"Yorktown posed a constant threat to Richmond both because of its proximity by land and the ease with which you could send large numbers of troops from its wharves to the Richmond & York River Railroad on the Pamunkey River," historian John V. Quarstein says, describing the historic Civil War stronghold that Colonial National Historical Park will recreate Saturday and Sunday through the living history programs of "Fort Yorktown Sesquicentennial Weekend."
"It would have been even more important had the North had more enterprising commanders and used its resources better."
Fortified by Confederate commander John B. Magruder as part of his 12-mile-long Warwick-Yorktown Defensive Line, the earthen ramparts ringing the old colonial town fell into disrepair soon after besieged Southern forces withdrew in early May 1862.
By late August, their condition was so bad that Union Maj. Gen. John J. Peck described them as "overgrown with noxious weeds, and the earth is saturated with human feces and decaying animal matter.
"The exterior ditch and exterior face of the work is in many places so much washed away and defaced as to form but little impediment to an assaulting column."
All that changed within weeks under Peck's supervision. But it wasn't until 1863 that the Union's investment began to pay off.
That May, Yorktown became the launching pad for more than 30,000 troops as they gathered from across Hampton Roads and shipped out to West Point for Maj. Gen. John A. Dix's Peninsula Campaign, which threatened Richmond in response to Robert E. Lee's march on Gettysburg.
Four months later, Maj Gen. Isaac J. Wistar led a combined force of several thousand infantry, cavalry and artillerymen as well as a dozen Union gunboats in an expedition across the York to Mathews County, where they turned the countryside upside-down in a punishing house-to-house search for Confederate blockade runners and merchant raiders.
Despite severe injuries that limited the use of his arms, Wistar proved so enterprising in his command that he also used Yorktown as the springboard for an ambitious raid on Richmond in February 1864, only to find himself bottled up at Bottoms Bridge because of a Union deserter's warning. He later moved out to help recover the retreating elements of the Kilpatrick-Dahlgren Raid on Richmond in early March, then joined the 33,000-man Army of the James as they passed through Yorktown in May for the Bermuda Hundred Campaign on the James River.
"It was like island-hopping in the Pacific during World War II," says Lee Hall Mansion curator J. Michael Moore.
"Yorktown was the place that you leap-frogged from whenever you wanted to threaten Richmond or the Middle Peninsula — and the importance of that role has been overlooked."
Defended by a garrison of as many as 4,000 infantry, artillery and cavalrymen, the fort sometimes boasted more troops than the Department of Virginia headquarters at Fort Monroe.
Three Union gunboats operated from its wharves on patrol and blockade duty, joined by a constant stream of transport ships and supply vessels.
Sutlers' stores sold all kinds of wares to the soldiers inside the fort, while outside their sprawling tent cities and the town's well-armed earthen walls the landscape was covered with the shanties of thousands of contraband slaves.
Quaker missionaries came at Wistar's invitation beginning in July 1863, building and operating the schools that taught the runaway blacks to read and write by the hundreds.
So bustling a place did the fort and harbor become that the enterprising troops opened their own photography studio. They also used confiscated presses from Williamsburg to publish "The Cavalier" newspaper.
"Wistar was the one who really beefed things up," Colonial National Historical Park historian Diane Depew says, describing how the energetic general transformed his command.
"Every building in the town was being used by the army — and outside the fort he ordered the construction of hundreds of contraband cabins in Slabtown."
By some accounts the number of refugee slaves grew to as many as 10,000 during the war, depriving the Confederacy of one of its chief assets.
Some fled from as far as away as Richmond, dodging Southern troops and slave hunting parties in a desperate attempt to reach the historic Revolutionary War battle ground that many identified with freedom.
That symbolic association only grew with the October 1863 arrival of the 4th and 6th United States Colored Troops infantry regiments, who were among the first black soldiers seen in Virginia.
Not only did they serve as models of resistance for the incoming contrabands but several men from the 4th also went on to win the Medal of Honor.
"By the summer of 1863, the Union had some real obligations to the huge number of contrabands gathered here — and this becomes an important recruiting area," Depew says.
"The competition between recruiting officers became so great that they started to fight over who had a right to be here."
Erickson can be reached at 757-247-4783. Find more stories on Hampton Roads history at dailypress.com/history and Facebook.com/hrhistory.
Want to go?
Fort Yorktown Sesquicentennial Weekend
What: Living history programs featuring nearly 100 re-enactors presenting Union infantry and cavalry encampments and drills, a Civil War hospital, courts martial, mail calls, refugee slaves and Quaker missionary work.
Where: Along Main and Nelson streets in the Yorktown historic area
When: 10 a.m.-4:30 p.m. Saturday and Sunday
Information: 757-898-2410 or http://www.nps.gov/colo