Gettysburg Campaign

In June 1863, as Gen. Robert E. Lee led the Army of Northern Virginia through Blue Ridge gaps to the Shenandoah Valley, Maj. Gen. J. E. B. Stuart's cavalry screened the army from Federal observation. The Union cavalry chief, Brig. Gen. Alfred Pleasonton, dispatched Brig. Gen. David M. Gregg to penetrate Stuart's screen. On 17 June, Gregg ordered Col. Alfred A. N. Duffié to reconnoiter from Aldie to Middleburg. Duffié drove off Confederate pickets there, alerting Stuart. Duffié withdrew south of Middleburg, but Brig. Gen. Beverly H. Robertson's brigade surrounded and almost wiped out Duffié's command before it escaped the next morning.