NPS-CWS&SS shows:

41st Battalion, Virginia Cavalry (White's)

41st Cavalry Battalion was organized in September, 1863, with four companies, later increased to seven. This unit skirmished in western Virginia and the Shenandoah Valley, then in April, 1864, merged into the 23rd Regiment Virginia Cavalry. Lieutenant Colonel Robert White was in command.

"A Guide to Virginia Military Organizations, 1861-1865" by Lee A. Wallace, Jr. basically confirms the NPS information, saying:

White, Robert., Maj., afterwards Col., 1863-1864
The 41st Bn, formerly known as Maj. Robert White's Bn. Va. Partisan Rangers, was organized by S.O. No. 222, A&IGO, dated September 18, 1863, with four companies. It was later increased to seven companies, and by S.O. No. 99, A&IGO, dated April 28, 1864, two companies of O'Ferrall's Bn Va, Cav., and Capt Calmes' Co Va. Cav., were added to it, forming the 23rd Regt Va. Cav.