At the outbreak of the Civil War, he enlisted as a private, but was soon appointed
aide-de-camp to General
Thomas A. Morris, with the rank of captain, and assisted in organizing six volunteer regiments. On June 12, 1861, he was made
colonel of the
17th Indiana Infantry and took part in the successful
West Virginia campaign under Major General
George B. McClellan. In December 1861, he was ordered to Louisville, Kentucky, and placed in command of a brigade consisting of the 17th Indiana, 6th Ohio, 43d Ohio, and
15th Indiana regiments, assigned to the division commanded by General
William "Bull" Nelson. Later that month, he was given charge of a brigade in
Thomas J. Wood’s division of
Don Carlos Buell’s forces in the
Army of the Ohio. His troops arrived at
Shiloh the day after fighting ended, but did take part in the
Siege of Corinth. Hascall was commissioned as a
brigadier general of volunteers on April 25, 1862. Having been transferred to the
Army of the Cumberland, he was put in command of a
brigade which fought through the
Kentucky Campaign. He continued to serve in Tennessee through March 1863. During the
Battle of Stones River (December 31, 1862 to January 3, 1863), he assumed command of the 1st Division when General Wood was wounded. During the battle, Hascall led reinforcements to the Round Forest where he took charge of the defense of that place and decided it had to be held at all costs. After the battle he was sent to
Indianapolis, Indiana, to take command of the District of Indiana, charged with returning deserters from Ohio, Illinois, and Indiana. He also suppressed dissident opinions in Indiana newspapers, including the
Plymouth Democrat. He then was transferred to the
Army of the Ohio and placed in command of the 3rd Division in the
XXIII Corps. Later that year, he took part in the battles the
defense of Knoxville (November to December, 1863). The next year Hascall commanded the 2nd Brigade, 2nd Division, XXIII Corps for the first part of the
Atlanta campaign. During the
battle of Resaca 2nd Division commander, Brig. Gen.
Henry M. Judah failed to reconnoiter a river valley to his front before attacking. During the attack Hascall's brigade accidentally crossed in front of Brig. Gen.
John M. Palmer's division before it deployed. Despite both units becoming intertwined, Judah pushed Hascall forward only to have his men get stuck in the muddy creek. On May 18 Hascall assumed command of the 2nd Division after General Judah was relieved of command. Hascall led the division throughout the rest of Atlanta Campaign. ==Postbellum career==