People were calm at first, but as the Confederates picked up speed, that spirit turned to alarm. The New York Times, for example, began with the headline “The Proposed Rebel Raid” on June 10, but it soon changed to “INVASION: The New Rebel Movement Northward,” which contained an enormous map of Maryland and southern Pennsylvania.

Lee’s invasion of Maryland, in September 1862, was well remembered, but he moved much more quickly this time. General Ewell’s corps was in southern Pennsylvania by June 25. Because J. E. B. Stuart’s men cut a telegraph line, official Washington, D.C., went more than twenty-four hours without any news, and by the last few days of June, the capital was in a state of near-panic.