The 43rd Regiment of Indiana Infantry was a volunteer infantry unit from the U.S. state of Indiana that served in the Union Army during the U.S. Civil War in the Western Theater. Though deployed at different times in support of Federal operations in Missouri, Tennessee, Kentucky and Mississippi, the majority of its combat service took place in Arkansas. During the ill-fated Camden Expedition (part of Nathaniel Banks' Red River Campaign), it was one of three infantry regiments that, along with the Thirty-sixth Iowa and Seventy-seventh Ohio infantry, comprised the 2nd Brigade of the Third Division commanded by General Frederick Salomon. This division and brigade formed part of the Union VII Corps under Major-General Frederick Steele. A sizable portion of the regiment was killed or captured a