The Federal generals were apparently satisfied with the victory and in spite of urgings from the Secretary of War, Stanton, to pursue Jackson they remained inactive for nearly a month. Banks assumed the offensive on April 17th, and surprised Ashby, taking one of his companies prisoner. The Virginians burned the railroad station at Mount Jackson and fell back while the Union cavalry established themselves at New Market. The Confederate General Ewell had a force of 8,000 men on the Upper Rappahannock which is some distance east of the mountains. This corps was left at its location in order to rush to the defense of Fredericksburg or Richmond or across the mountains to the Valley. Jackson knew that he must not allow Banks to control the mountain pass, thus severing communication between the two Confederate forces. He determined upon a forced march for his men and on the eighteenth they reached Harrisonburg. He continued over to Swift Run Gap and encamped near there. Banks followed his cavalry to New Market, crossed over to Luray and seized the bridges, driving back a detachment of Jackson's men sent there to defend them. Later he sent two of his five brigades to Harrisonburg and the rest stayed at New Market. Jackson's next move was to McDowell, a town about twenty-seven miles northwest of Harrisonburg. The march was made in the most circuitous manner: from Swift Run Gap to Port Republic, to Brown's Gap which is about twelve miles southeast of their camp at Elk Run Valley, to Staunton and then west to McDowell. This strategy was used so that he might deceive Banks, Fremont and Milroy, the Federal commanders in and near the Valley, into thinking for a while that he was leaving the Valley to join forces at Richmond. Jackson proposed to strike each Union force located in this section of Virginia but he believed an encounter with Milroy commanding the weakest corps should be made before attacking Banks. The Battle of McDowell occurred on May 8th, and was a victory for Jackson. He followed the enemy in their retreat as far as Franklin. A squadron of Ashby's cavalry spent much time in blocking any of the passes which Fremont might use in crossing the mountains to reinforce Banks. Bridges were burned and rocks and trees were placed across the roadways. Jackson's object was thus thoroughly achieved: "All combination between the Federal columns, except by long and devious routes, had now been rendered impracticable; and there was little fear that in any operations down the Valley his own communications would be endangered. The McDowell expedition had neutralized, for the time being, Fremont's 20,000 men; and Banks was now isolated, exposed to the combined attack of Jackson, Ewell and Edward Johnson."