Maj. Gen. John Pope's Union Army of Virginia and Gen. Robert E. Lee's Army of Northern Virginia pursued aech other across the Rappahannock River in mid-August. Pope had only to protect the fords and await the arrival of the leading elements of the Army of the Potomac. Lee had to act to prevent this juncture. Wherever the Confederates probed for a crossing, Federals banned the way. Maj. Gen. J.E.B. Stuart, Lee's cavalry commander, proposed a raid to sever the Orange & Alexandria Railroad, the Union army's main supply line. Lee approved.
Stuart, with about 1,500 horseman and 2 cannons, crossed the Rappahannock at Waterloo Bridge on the 22nd. Skirting Pope's right, the Confederate cavalrymen entered Warrenton, Virginia, where they learned that there hadn't been any Federals for days. Stuart continued, angling his column towards Catlett's Station and the railroad bridge over Cub Run. As the Confederates rode, a violent thunderstorm erupted, with drenching rain and gusting winds.
Halting short of Catlett's in the evening, the Confederates quietly captured Union sentinels. From the Federals, Stuart learned that Catlett's was Pope's headquarters. A captured black Contraband agreed to lead the Confederates to Pope's tent. Stuart hurriedly deployed his troopers, ordering them to scream the "Rbel Yell" when the bugle sounded charge.
Through the lashing storm came the pistol-firing Confederates. Most of the Federals completely surprised, surrendered immediately. A handful of Pennsylvania infantry fired from the depot until the charging Confederates vaulted their horses onto the platform and crashed into the building. Within minutes, Stuart's troopers had seized hundreds of horses and mules, 300 prisoners, and Pope's hat, cloak, one of his dress uniforms, his dispatch book, and the army's money chest. A detachments of Confederates endeavored to burn the railroad tretle, but the rain and winds prevented it.
Stuart finally withdrew shortly before dawn, his elated men returning unmolested to the south side of the Rappahannock. His seizure of Pope's papers provided Lee with valuable information; the Union general's uniform was placed on public display in Richmond. On the 24th, Lee, with intelligence gained, conferred with Maj. Gen. Thomas J. "Stonewall" Jackson, outlining his plans for what would become the 2nd Manassas/Bull Run Campaign.