Already looking to the future, the B&O had purchased a lot in Harpers Ferry near the convergence of the Potomac and Shenandoah Rivers the previous year, where they constructed a ticket office and several other buildings to service the railroad. Once trains began arriving in Harpers Ferry the railroad once again hit a snag. Hoping to continue its tracks down the Winchester and Potomac line, the B&O entered negotiations to lease several miles of the W&P so that their trains could travel on a direct route from their bridge across the Potomac to a point in the Shenandoah Valley where it could make a gentle turn to the northwest towards Martinsburg. For unknown reasons, however, the W&P refused to lease their tracks, forcing the B&O to reach an agreement with the federal government (which had purchased land for an armory in the town). Eventually, the B&O was able to finalize this agreement and built an elevated track along the edge of the armory grounds. The new route forced the B&O to turn their tracks at almost a 90-degree angle once they crossed the Potomac Bridge, a severe turn that promised a continual threat of disaster until the rerouting of the tracks at the end of the nineteenth century. After this turn was added and the railroad left Harpers Ferry, it reached Martinsburg on May 21, 1842 and Cumberland, Maryland six months later. It took a full decade more for it to make its way to its final destination at Wheeling.
In the meantime, Harpers Ferry and its new B&O ticket office had become a bustling center of activity as a result of the influx of goods and passengers being transported through the area from east to west and vice versa. Among these passengers were runaway slaves fleeing bondage with the help of Underground Railroad conductor John Fairfield, an abolitionist known for going to extraordinary lengths to secure the freedom of slaves and reconnect them with their families. On many occasions, Fairfield posed as a slave trader and resided in a Southern community for months to gain the trust of local white residents before escaping the area with a large number of slaves. In one such effort he masqueraded as an undertaker and escaped with twenty-eight slaves in a staged funeral procession, and in another convinced salt miners near Charleston to fund the construction of boats to transport salt to market on the Kanawha River before promptly loading the boats with the miners’ slaves and escaping with them under cover of darkness. Much of Fairfield’s activity, however, took place in Harpers Ferry, where he would use wigs and makeup to disguise light-skinned slaves, purchase tickets for them, and send them as passengers on the B&O west past the dangerous turn through the armory toward Pittsburgh or east to Carroll County, Maryland where they would turn north to Pennsylvania. Fairfield continued his efforts for twelve years before disappearing in 1860 or 1861. An unidentified man matching his description died at the time of his disappearance organizing a mass escape of slaves in Cumberland County, Tennessee.
By then, however, the nation had erupted in Civil War and Harpers Ferry had become the focus of much military scrutiny. Because the B&O was a key route for the transportation of military personnel and materiel from east to west and Harpers Ferry held a strategically important location at the railroad’s crossing of the Potomac, it almost immediately came under attack by Union and Confederate forces. After the Virginia Assembly voted to provisionally secede from the United States on April 17, 1861 the governor of Virginia, John Letcher, ordered militia troops from Charleston and Winchester under Colonel Kenton Harper to occupy the armory at Harpers Ferry, which Union forces burned hours before Harper’s arrival on April 18. On April 27, the governor ordered then Colonel Thomas J. Jackson to relieve Harper, after which Jackson promptly arrested Brigardier General William Selby Harney as he traveled on the train through Harpers Ferry from St. Louis to Washington, D.C. Eager to disrupt the flow of Union goods on the railways through the town, Jackson devised a plan to destroy portions of the B&O from Martinsburg to Point of Rocks. Putting this plan into effect on May 23, Jackson cut off the lines at those two points and allowed the trains to continue moving into Harpers Ferry on schedule. The engines and their cargo thus bottlenecked in the town, Jackson began plans to haul his booty down the Winchester and Potomac. By June this goal had been largely accomplished, as had the destruction of key portions of the B&O track (including the bridge at Harpers Ferry).