He also served as regular soldier in Elijah V. White's 35th Battalion, Virginia Cavalry, nicknamed the "Comanches."

His legacy is surrounded in controversy as Federal soldiers and Union sympathizers in Loudoun County accused him of committing war atrocities, including slave-rustling, while pro-Southern Loudoun residents claimed him to be a hero, second only to Mosby in local popularity.

[1][permanent dead link‍] At the start of the American Civil War Mobberly enlisted in Company A of the 35th Battalion at Hillsboro on September 15, 1862.

He saw his first significant combat action at the Battle of Brandy Station on June 9, 1863, where he had a horse shot out from under him.

On January 17, 1865, while serving as a scout, Mobberly led the advance guard in the George's Schoolhouse Raid.