On June 28, 1863, a veteran Confederate division under Major General Jubal Early entered York County with the goal of driving off local militia defenders and holding York for ransom. Near Weiglestown, Early dispatched Colonel William French with most of the 17th Virginia Cavalry on a mission across Manchester Township. His objective? Seize and burn the twin railroad bridges over Conewago Creek near York Haven. Their destruction would severely hamper traffic between Baltimore and Harrisburg on the Northern Central Railway.
Unknown to Early, the Yankees had, several days before, dispatched nearly a thousand fresh soldiers to York County to guard important bridges, the Howard Tunnel, and key supply routes. They were commanded by Colonel William Thomas (a wealthy Philadelphia businessman and Republican politician who was a personal friend of Abe Lincoln). Most of Thomas's men worked for him in the Customs House and Port of Philadelphia, but all were equipped with the latest in rifled muskets. The cavalrymen had pistols and sabers, with an occasional carbine. A clash of arms loomed, and the unsuspecting Confederate cavalrymen would be outnumbered and outgunned.
