On Thursday, June 25, 1863, Robert E. Lee sent General Jeb Stuart to reconnoiter with his Confederate cavalry, passing between the Federal army and Washington, D.C. Such a raid would, of course, panic the North.
Thus began an operation which deprived Lee of his cavalry for much of the Gettysburg campaign. Lee, a masterful tactician who knew by heart every topographical feature of his beloved Virginia, knew little about Northern geography, and Confederate maps proved to be inaccurate.
By authorizing Stuart’s raid, Lee deprived himself of valuable intelligence about his enemies’ strengths and about the ground upon which subsequent battles would be fought. The decision to allow Stuart to temporarily leave his army was one of the most critical mistakes which Lee made in the entirety of the American Civil War.