The Indiana 20th Regiment was a volunteer infantry regiment that served in the Union Army during the American Civil War. Organized in 1861, it was part of the Indiana Volunteer Infantry and played a significant role in various battles throughout the war, including the Battle of Shiloh and the Battle of Vicksburg. The regiment was mustered in for a three-year term and consisted of men from various counties in Indiana. It was known for its bravery and discipline, contributing to the Union's efforts to preserve the nation. The Indiana 20th Regiment was mustered out in 1865 after the war ended.