 During his first day commanding forces, on April 27, 1861, Col Jackson's men arrested one of the only four general officers in the regular army at that time, Brigadier General William Selby Harney, at Harpers Ferry, while he was taking a train to Washington, D.C.He was commanding the Department of the West, and was traveling from his headquarters in St. Louis, Missouri.Sometime following this, Col Jackson, while familiarizing himself with the B&O Railroad line, inspected Captain John D. Imboden's (later a CSA Brigadier General) assigned post, possessing the bridge across the Potomac River at Point of Rocks, Maryland.