The regiment remained in the Shenandoah Valley until August 1862 when they joined Pope's army and moved south to engage Robert E. Lee's Army of Northern Virginia. They arrived the day after the Battle of Cedar Mountain, and joined Pope's army in its retreat from that Confederate victory. After a series of minor actions along the Rappahannock, Pope's forces met Jackson's half of Lee's army near Manassas Station. Lee had divided his army into wings led by Jackson and Lt. Gen. James Longstreet and sent Jackson's force to raid Pope's rear to cut his supply line. Pope believed he had a chance to destroy the Army of Northern Virginia one half at a time, and made the decision to attack. Jackson's men struck the first blow, however, and drove off a portion of the Union force. The next day, having taken up a strong defensive position along an unfinished railroad, Jackson awaited Pope's advance. Pope obliged him, sending the Army forward against Jackson's lines. The 68th and the rest of Sigel's corps occupied the middle of the advancing line. They were unable to break Jackson's lines, and withdrew. The Cameron Rifles had seen some action at Cross Keys, but this was their first experience of fierce fighting and they acquitted themselves well, despite the failure of the attack.