Question: What major American war did the Union corps commander born in 1827 fight in?

<P0-S0>  After the surrender of Confederate forces, Slocum was given command of the Department of Mississippi. <P0-S1>  His successful defense of Culp’s Hill was crucial to the Union victory at Gettysburg. <P0-S2>  During the war, he was one of the youngest major generals in the Army and fought numerous major battles in the Eastern Theater and in Georgia and the Carolinas. <P0-S3>  While commanding a regiment, a brigade, a division, and a corps in the Army of the Potomac, he saw action at Bull Run, the Peninsula, South Mountain, Antietam, Chancellorsville, and Harpers’ Ferry. <P0-S4> Henry Warner Slocum, Sr. (September 24, 1827 – April 14, 1894), was a Union general during the American Civil War and later served in the United States House of Representatives from New York. <P0-S5>  He then served as occupation commander of Atlanta. <P0-S6>  Slocum declined an appointment in the postwar Army. <P0-S7>  After the fall of Vicksburg, Slocum was appointed military commander of the district. <P0-S8>  At Gettysburg, he was the senior Union General in the Field. <P0-S9>  During the battle, he held the Union right from Culp’s Hill to across the Baltimore Pike. <P0-S10>  Slocum was appointed the commander of the left wing of Sherman’s march through Georgia and the Carolinas, commanding the XIV and XX Corps, comprising the Army of Georgia. <P0-S11>  Slocum participated in the Atlanta campaign and was the first commander to enter the city on September 2, 1864. <P0-S12>  The March to the Sea and the Carolinas campaign were crucial to the overall Union victory in the Civil War. <P0-S13>  He was a successful political leader, businessman and railroad developer. <P0-S14>  During this campaign, he captured the capitol of Georgia, Milledgeville, and the seaport of Savannah. <SEP> <P1-S0> John Gibbon (April 20, 1827 – February 6, 1896) was a career United States Army officer who fought in the American Civil War and the Indian Wars. <SEP> <P2-S0> The 12th West Virginia Volunteer Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War. <P2-S1>  The regiment was particularly distinguished for its successful attack on Fort Gregg during the 1864 to 1865 Siege of Petersburg, receiving a golden eagle for its flagstaff as a token of appreciation from corps commander John Gibbon. <SEP> <P3-S0> Roman Ivanovich Panin (Russian: Роман Иванович Панин ; 28 September 1897 – 1 June 1949) was a Soviet major general from during World War II. <P3-S1>  An Imperial Russian Army junior officer in World War I, he joined the Red Army in 1919. <P3-S2>  Panin fought in the Russian Civil War and continued to serve after the end of the Russian Civil War. <P3-S3>  He was an advisor to the National Revolutionary Army between 1938 and 1939. <P3-S4>  Later he participated in the Soviet-Finnish war as a corps commander, and during World War II as the commander of the 14th Army, commanding the defense of Murmansk during Operation Silver Fox. <P3-S5>  Panin became commander of the 2nd Reserve Army in May 1942 and two months later became a lecturer at the Frunze Military Academy. <P3-S6>  In February 1943 he became Volkhov Front chief of combat training and in September led the 7th Rifle Corps. <P3-S7>  After participating in the Leningrad–Novgorod Offensive, Panin briefly led the 99th Rifle Corps. <P3-S8>  In July 1944, Panin became deputy commander of the 5th Army. <P3-S9>  Hospitalized in February 1945 during the East Prussian Offensive, Panin did not see further action. <P3-S10>  After recovering he became an instructor at the Frunze Military Academy and retired in 1949. <P3-S11>  He died shortly afterwards.