Civil War Union Army Officer. He served as Colonel and commander of the 44th Indiana Volunteer Infantry, rising to that rank from 1st Lieutenant. He was wounded in the hand at the April 1862 Battle of Shiloh, he served until he died of disease contracted during his field service. Born in Vermont, previous to the Civil War he served as Postmaster of Pleasant Lake, Indiana, and Sheriff of Steuben County, Indiana. He volunteered his service when the war began, and was commissioned as 1st Lieutenant in Company K, 44th Indiana Volunteer Infantry on November 22, 1861. On December 10, 1861 he was promoted to Captain and commander of Company K. He led his men in the April 1862 Battle of Shiloh, Tennessee, where his regiment suffered 198 casualties, and he himself was wounded by a gunshot in his hand. The unit subsequently fought in the April-May 1863 Siege of Corinth, Mississippi, and the October 1862 Battle of Perryville, Kentucky. On December 6, 1862 he was promoted to Lieutenant Colonel, and would assume command of the 44th Indiana Infantry during the December 1862-January 1862 Battle of Murfreesboro, Tennessee, when Colonel William C. Williams was captured by Confederate forces. After Colonel William was exchanged after being imprisoned by the Rebels, he resigned, and Simeon Aldrich was then appointed Colonel on July 27, 1863. He led the regiment in the September 1863 Battle of Chickamuaga, Georgia, and the November 1863 Battle of Missionary Ridge, Tennessee. In November 1863 the regiment was assigned to provost duty in Chattanooga, Tennessee, where it would remain for the rest of the war, and Colonel Aldrich was assigned as the Provost Marshal for the city. He commanded the regiment until early August 1864, when he was relived from duty and allowed to return to his home due to his suffering from dysentery. He was not home long before he succumbed to the disease on August 15, 1864.