The Battle of Princeton Court House was fought May 15–17, 1862, in Mercer County, Virginia (now West Virginia) in conjunction with Stonewall Jackson's Valley Campaign. It was a minor victory for the Confederate States Army.
By early May 1862, Union forces were positioned to invade Virginia at two places. Brig. Gen. Robert H. Milroy's column, its axis of march the Staunton-Parkersburg Turnpike, advanced from Cheat Mountain and occupied in succession Camp Allegheny, Monterey, McDowell, and Shenandoah Mountain. Retreating before the oncoming Federals, Confederate Brig. Gen. Edward "Allegheny" Johnson pulled back to Westview, six miles west of Staunton.
Union soldiers of Brig. Gen. Jacob D. Cox's District of Kanawha threatened the East Tennessee & Virginia Railroad. By mid-May, the Federals, although ousted from Pearisburg, held Mercer County and braced for a lunge at the railroad. Confederate Brig. Gen. Humphrey Marshall arrived from Abingdon, Virginia, with the Army of East Kentucky. Seizing the initiative, Marshall bested Cox's two brigades during three days of fighting, May 15 to May 17, in Mercer County, centering on Princeton Courthouse. There were 129 casualties in total.
Breaking contact with the Confederates on the night of May 17, Cox withdrew 20 miles (30 km). Col. George Crook, commanding Cox's 3rd brigade, marched to and occupied the city of Lewisburg, where on May 23 he defeated Brig. Gen. Henry Heth's brigade. He withdrew upon learning that Thomas J. "Stonewall" Jackson's army had routed a Union division at Winchester on May 25.