Cross Roads, Union cavalry attacked the column, capturing 134 wagons, 600 horses and mules, and 645 prisoners, about half of whom were wounded. These losses so angered Stuart that he demanded a court of inquiry to investigate. Early on July 4 Meade sent his cavalry to strike the enemy's rear and lines of communication so as to "harass and annoy him as much as possible in his retreat." Eight of nine cavalry brigades (except Col. John B. McIntosh's of Brig. Gen. David McM. Gregg's division) took to the field. Col. J. Irvin Gregg's brigade (of his cousin David Gregg's division) moved toward Cashtown via Hunterstown and the Mummasburg Road, but all of the others moved south of Gettysburg. Brig. Gen. John Buford's division went directly from Westminster to Frederick, where they were joined by Merritt's division on the night of July 5. Late on July 4, Meade held a council of war in which his corps commanders agreed that the army should remain at Gettysburg until Lee acted, and that the cavalry should pursue Lee in any retreat. Meade decided to have Brig. Gen. Gouverneur K. Warren take a division from Sedgwick's VI Corps to probe the Confederate line and determine Lee's intentions. By the morning of July 5, Meade learned of Lee's departure, but he hesitated to order a general pursuit until he had received the results of Warren's reconnaissance. The Battle of Monterey Pass began as Brig. Gen. Judson Kilpatrick's cavalry division easily brushed aside Brig. Gen. Beverly Robertson's pickets and encountered a detachment of 20 men from the Confederate 1st Maryland Cavalry Battalion, under Capt. G. M. Emack, that was guarding the road to Monterey Pass. Aided by a detachment of the 4th North Carolina Cavalry and a single cannon, the Marylanders delayed the advance of 4,500 Union cavalrymen until well after midnight. Kilpatrick ordered Brig. Gen. George A. Custer to charge the Confederates with the 6th Michigan Cavalry, which broke the deadlock and allowed Kilpatrick's men to reach and attack the wagon train. They captured or destroyed numerous wagons and captured 1,360 prisoners – primarily wounded men in ambulances – and a large number of horses and mules. As Meade's infantry began to march in pursuit of Lee on the morning of July 7, Buford's division departed from Frederick to destroy Imboden's train before it could cross the Potomac. At 5 p.m. on July 7 his