On May 23, by a swift, silent march of his little army of fifteen thousand men, he took Banks completely by surprise, crushed and captured his advance guard at Fort Royal, struck him in the flank and drove him back into Strassburg, through Winchester, and hurled his shattered army in confusion and panic across the Potomac on its Washington base. Desperate alarm swept the Capital of the Union. Stanton, the Secretary of War, issued a frantic appeal to the Governors of the Northern States for militia to defend Washington. Panic reigned in the cities of the North. Governors and mayors issued the most urgent appeals for enlistments. Fremont was ordered to move with all possible haste and form a juncture with a division of McDowell's army and cut off Jackson's line of retreat. The wily Confederate General wheeled suddenly and rushed on Fremont before Shields could reach him. On June 8, at Cross Keys, he crushed Fremont, turned with sudden eagle swoop and defeated Shields at Port Republic. Washington believed that Jackson commanded an enormous army, and that the National Capital was in danger of his invading host. The defeated armies of Milroy, Banks, Fremont and Shields were all drawn in to defend the city. In this campaign of a few weeks Jackson had marched his infantry six hundred miles, fought four pitched battles and seven minor engagements. He had defeated four armies, each greater than his own, captured seven pieces of artillery, ten thousand stands of arms, four thousand prisoners and enormous stores of provisions and ammunition. It required a train of wagons twelve miles long to transport his treasures--every pound of which he saved for his Government. He was never surprised, never defeated, never lost a train or an organized piece of his army, put out of commission sixty thousand Northern soldiers under four distinguished generals and in obedience to Lee's command was now sweeping through the mountain passes to the relief of Richmond. While Jackson was thus moving to join his forces with Lee, Washington was shivering in fear of his attack. On the day Jackson was scheduled to fall on the flank of McClellan's besieging army Lee moved his men to the assault. The first battle which Johnston had joined at Seven Pines had only checked McClellan's advance. The Grand Army of the Potomac still lay on its original lines, and McClellan had used every day in strengthening his entrenchments. Lee had built defensive works to enable a part of his army to defend the city while he should throw the flower of his gray soldiers on his enemy in a desperate flank assault in cooeperation with Jackson. On the arrival of his triumphant lieutenant from the Shenandoah Valley Lee suddenly sprang on McClellan with the leap of a lion. The Northern Commander fought with terrible courage, amazed and uneasy over the discovery that Jackson had suddenly appeared on his flank.