Thomas F. Harney was a Confederate explosives expert, who was arrested by the Union Army in the final days of the US Civil War, seemingly en route to bomb the White House. While his initial capture was dismissed as immaterial, as he explained he was a simple engineer delivering ordnance to Mosby, postwar memoirs of Mosby's partisans noted Harney's capture was disastrous and it became clear that he'd been intended to carry out the bombing of the White House.