The specific incident of September 29, 1862, was a raid on the Town of Warrenton by a 500-man Federal cavalry detachment, led by Lt. Col. Joseph Karge, First New Jersey Cavalry. According to a later report by Karge, the raiding party entered the undefended town and found it filled with wounded and sick Confederate soldiers. Before leaving and heading north, the Federal troopers "captured" and then issued parole "papers" to "about 1,300 to 1,400" Southerners.
Karge's full report describes the terrible conditions of the wounded and sick Confederates in the town.
Jim Parrish