and to push forward over the Rappahannock to Manassas. Believing that Lee's army was stretched along the Culpepper road he determined to attack the weakened line at Fredericksburg. Two pontoon bridges were thrown over the river at Franklin's Crossing, and on June 6th Howe's division crossed. Hill's corps advanced in opposition and Lee prepared to recall Ewell if he found it necessary. When Hooker saw this display of force he checked his advance, and failed to learn how small was the force opposed to him. Learning that the Confederate cavalry under General Stuart was stationed at Culpepper, Howe determined to make a cavalry reconnoissance on a large scale in that direction. His object was to learn whether Stuart meditated a raid or was trying to cover the movements of infantry. In the meantime Longstreet arrived at Culpepper and joined Stuart.
Lee's plan of invasion was now in full operation. Stuart was to conceal the movements of the infantry by menacing the Unionists near Warrenton, while the army was to proceed to the northwest by way of Sperryville and Thornton's Gap and so reach the valley of the Shenandoah. This would leave the Union army in the rear.
At daybreak of the 9th, Pleasanton's two columns, seven thousand five hundred cavalry and three thousand infantry, crossed the Rappahannock. The Confederates, deeply occupied with their own plans, and suspecting nothing, were taken by surprise, and Stuart narrowly escaped losing his artillery. He was driven back and lost his baggage, and in it were found instructions revealing Lee's plans.
Stuart was preparing to attack Buford's division, when he learned that Greggs' division, having crossed the river unobserved, was coming up in his rear and was then engaged with Robertson's brigade at Fleetwood Hill. Leaving the brigades of W. H. F. Lee and Fitzhugh Lee to resist Buford, Stuart hurried back and attacked Gregg.
