Late in the morning of June 9, 1863, during the Battle of Brandy Station, Union cavalry under Col. Alfred Duffie approached Hansborough Ridge from the south along what is now Route 3 after crossing the Rappahannock River earlier that morning at Kelly's Ford, while other Union troops under Brig. Gen. John Buford crossed at Beverly Ford. Duffie's 2nd Division of the Army of the Potomac's Cavalry Corps, about 3000 men and 6 cannon, had been ordered to reconnoiter Stevensburg and the Germanna Plank Road for evidence of Confederate infantry, then join other Union columns at Brandy Station before a joint advance toward Culpeper Court House. At Hansborough Ridge, about 200 troops of the 2nd South Carolina Cavalry under Col. Mathew C. Butler blocked the Federals. After Duffie hesitated, the 1st Massachusetts Cavalry charged, broke through Butler's thin line, and struck the 4th Virginia Cavalry as it was still deploying. The outnumbered Confederates then dashed for Norman's Mill Ford and crossed to the north side of Mt. Run, where the 4th Virginia Cavalry's lone cannon guarded the only ford where horses could cross the stream. Unable to follow across Mt. Run, Duffie gave the Confederates their first breathing spell of the morning, and they immediately began organizing their defense behind the natural barrier. Hansborough Ridge later served as the site of the Army of the Potomac's 2nd Corps and 2nd Cavalry Division winter camps during the winter of 1863-1864, and Signal Hill at the far left was used as a signal station throughout the war.
