By early May 1862 Union forces in today's West Virginia were positioned to breach the Alleghenies and debouch into Virginia's Great Valley at two points more than 100 miles apart.
Union Brigadier General Robert H. Milroy's column, its axis of march the Staunton-Parkersburg Turnpike, advanced from Cheat Mountain and occupied in succession Camp Allegheny, Monteray, McDowell, and Shenandoah Mountain.
Retreating before the oncoming Federals, Confederate Brigadier General Edward Johnson pulled back to Westview, six miles west of Staunton.
Union soldiers of Brigadier General Jacob D. Cox's District of Kanawha threatened the East Tennessee & Virginia Railroad. The Federals by mid-May, although ousted from Pearisburg, held Mercer County and braced for a lunge at the railroad. Confederate Brigadier General Humphery Marshall arrived from Abingdon, Virginia, with the Army of East Kentucky. Boldly seizing the initiative, Marshall bested Cox's two brigades during three days of fighting, May 15-17, in Mercer County centering on Princeton Courthouse.
Breaking contact with the Confederates on the night of the 17-18, Cox withdrew 20 miles to Camp Flat Top. Col. George Crook, commanding Cox's 3rd brigade, marched via the James and Kanawha Turnpike and occupied Lewisburg, where on May 23 he defeated Brigadier General Henry Heth's brigade.
Upon learning that Major General Thomas J. "Stonewall" Jackson's army had routed Major General N.P. Banks' division at Winchester (March 25) and driven it across the Potomac, Crook evacuated Lewisburg and pulled back to Meadow Bluff.
Result(s): Confederate victory
Location: Mercer County
Campaign: Jackson's Shenandoah Valley Campaign (1862)
Date(s): May 15-17, 1862
Principal Commanders: Brigadier General Jacob D. Cox [US];
Brigadier General Humphery Marshall [CS]
Forces Engaged: District of the Kanawha [US]; Army of East Kentucky and Col. Gabriel C. Wharton's Brigade, Department of Southwest Virginia [CS}
Estimated Casualties: 129 total (US 23k/69w/21m; CS incomplete, Marshall 4k/12w, Wharton no report)