across Cedar Creek. Jackson's advance was stopped, however, by the Union division of Brig. Gen. James B. Ricketts. By now Jackson had learned that Pope's corps were all together, foiling his plan of defeating each in separate actions. He remained in position until August 12, then withdrew to Gordonsville. Lee advances to the Rappahannock On August 13, Lee sent Longstreet to reinforce Jackson, and on the following day Lee sent all of his remaining forces (except for two brigades) after he was certain that McClellan was leaving the Peninsula. Lee arrived at Gordonsville to take command on August 15. He massed the Army of Northern Virginia south of Clark's Mountain and planned a turning movement to defeat Pope before McClellan's army could arrive to reinforce it. His plan was to send his cavalry under Stuart, followed by his entire army, north to the Rapidan River on August 18, screened from view by Clark's Mountain. Stuart would cross and destroy the railroad bridge at Somerville Ford and then move around Pope's left flank into the Federal rear, destroying supplies and blocking their possible avenues of retreat. Logistical difficulties and cavalry movement delays caused the plan to be abandoned. On August 20–21, Pope withdrew to the line of the Rappahannock River. He was aware of Lee's plan because a Union cavalry raid captured a copy of the written order. Stuart was almost captured during this raid; his cloak and plumed hat did not escape, however, and Stuart retaliated on August 22 with a raid on Pope's headquarters at Catlett's Station, capturing the Union commander's dress coat. Stuart's raid demonstrated that the Union right flank was vulnerable to a turning movement, although river flooding brought on by heavy rains would make this difficult. It also revealed the plans for reinforcing Pope's army, which would eventually bring it to the strength of 130,000 men, more than twice the size of the Army of Northern Virginia. Skirmishing on the Rappahannock The two armies fought a series of minor actions August 22–25 along the Rappahannock River, including Waterloo Bridge, Lee Springs, Freeman's Ford, and Sulphur Springs, resulting in a few hundred casualties. Together, these skirmishes kept the attention of both armies along the river. Heavy rains had swollen the river and Lee was unable to force a crossing. Pope considered an attack across the river to strike Lee's right flank, but he was also stymied by