William Neil Dennison was a United States Army artillery officer during the American Civil War and an attorney and business speculator during his postwar career.
Dennison 1LT Wm Neil Battery A 2nd US Artillery at Fair Oaks 1862 detail of LC B811 435
William Neil Dennison, ca 1880s. Library of Congress
For this article, “Company A” and “Battery A” are interchangeable. A battery of four to six cannons, with two to three two-cannon sections was the basic unit of the artillery branch. The organization
William Neil Dennison
…throughout the Civil War, almost entirely with the Horse Artillery Brigade. He gained most of his experience while serving as a section chief with Battery A, 2nd U.S. Artillery under the command of Captain John C. Tidball. During the Peninsula campaign of 1862, Dennison commanded the rear (left) section of Tidball's "flying…
U.S. Army captain James Duncan of Illinois received three brevets—major, lieutenant-colonel, and colonel—for his actions in the Mexican War. Pictured in 1848 as colonel by Mathew Brady
An artillery duel during the Battle of Monterrey
Fair Oaks, Va., vicinity. Lieutenant Robert Clarke, Capt. John C. Tidball, Lieutenant William N. Dennison, and Capt. Alexander C.M. Pennington.
Harry Benson's Battery A, of the 2nd U.S. Artillery, and Horatio Gates Gibson's Batteries C and G, combined of the 3rd U.S. Artillery, near Fair Oaks, Virginia.