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

Roman Ivanovich Panin (Russian: Роман Иванович Панин ; 28 September 1897 – 1 June 1949) was a Soviet major general from during World War II.  An Imperial Russian Army junior officer in World War I, he joined the Red Army in 1919.  Panin fought in the Russian Civil War and continued to serve after the end of the Russian Civil War.  He was an advisor to the National Revolutionary Army between 1938 and 1939.  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.  Panin became commander of the 2nd Reserve Army in May 1942 and two months later became a lecturer at the Frunze Military Academy.  In February 1943 he became Volkhov Front chief of combat training and in September led the 7th Rifle Corps.  After participating in the Leningrad–Novgorod Offensive, Panin briefly led the 99th Rifle Corps.  In July 1944, Panin became deputy commander of the 5th Army.  Hospitalized in February 1945 during the East Prussian Offensive, Panin did not see further action.  After recovering he became an instructor at the Frunze Military Academy and retired in 1949.  He died shortly afterwards. <SEP> 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.  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.  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.  At Gettysburg, he was the senior Union General in the Field.  During the battle, he held the Union right from Culp’s Hill to across the Baltimore Pike.  His successful defense of Culp’s Hill was crucial to the Union victory at Gettysburg.  After the fall of Vicksburg, Slocum was appointed military commander of the district.  Slocum participated in the Atlanta campaign and was the first commander to enter the city on September 2, 1864.  He then served as occupation commander of Atlanta.  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.  During this campaign, he captured the capitol of Georgia, Milledgeville, and the seaport of Savannah.  In the Carolinas campaign, Slocum’s army saw victories in the battles of Averasborough and Bentonville, North Carolina.  The March to the Sea and the Carolinas campaign were crucial to the overall Union victory in the Civil War.  After the surrender of Confederate forces, Slocum was given command of the Department of Mississippi.  Slocum declined an appointment in the postwar Army.  He was a successful political leader, businessman and railroad developer. <SEP> 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> The 12th West Virginia Volunteer Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War.  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.