On September 10, 1862, Gen. Robert E. Lee ordered Gen. Thomas J. "Stonewall" Jackson and a detachment of 15,000 men, about two-thirds of the Army of Northern Virginia, to capture the Union garrison at Harpers Ferry and secure Confederate lines of communication with Virginia. Jackson first planned to follow the Sharpsburg Road from Frederick to the Potomac River, but decided instead to cross the river at Williamsport, where he could easily engage the nearby Federal garrison at Martinsburg, Virginia. When Jackson’s column forded the river there on September 11, the outnumbered garrison fled to Harpers Ferry. By taking the longer route, however, Jackson fell behind schedule. He did not capture Harpers Ferry until September 15 and rejoined Lee on the Antietam battlefield barely in time to save the Confederate army.
