Even before the guns fell silent at Gettysburg, Robert E. Lee was preparing for the arduous task of getting his defeated Confederate army back safely into northern Virginia. It was an enormous, complex, and exceedingly dangerous undertaking--all in a pouring rainstorm and all under the shadow of a possible attack from the Federal Army of the Potomac.Lee first needed to assemble two wagon trains, one to transport the wounded and the other to deliver the tons of supplies acquired by the army as it roamed across Pennsylvania and Maryland on the way to Gettysburg. Once the wagon trains were set, he mapped routes for his infantry and artillery on different roads to speed the journey and protect his command.The victor of Gettysburg, George Meade, remained unsure of Lee's next move and dispatched Maj. Gen. John Sedgwick's VI Corps on a reconnaissance-in-force. The thrust found the Confederate army in full retreat: Lee was heading back to Virginia. Meade launched a pursuit along different routes hoping to catch his beaten enemy without unduly exposing his own battle-exhausted troops to a devastating counterattack or ambush.Union cavalry moved out after the vulnerable Confederate wagon trains. The encounters that followed--including several engagements with Jeb Stuart's horsemen--resulted in the loss of hundreds of vehicles, the capture of large numbers of wounded, and the seizure of tons of valuable supplies. The majority of Lee's wagons reached Williamsport, Maryland, only to find the pontoon bridge had been cut loose by Union troops. Lee's army, meanwhile, reached Hagerstown, Maryland, largely unscathed and erected a strong defensive line while racing to build a pontoon bridge across the swollen Potomac at Falling Waters.Even as Meade hurriedly pursued Lee, he sought opportunities to launch an attack that might crush Lee's army--and even end the war--once and for all. Bradley M. Gottfried and Linda I. Gottfried share the high-stakes story of Gettysburg's aftermath in Race to the Potomac: Lee and Meade After Gettysburg, July 4-14, 1863.