 Complete the following phrase:  Oliver graduated from St. Johns College in New York. He moved to Michigan and worked as a pharmacist. When the Civil War began he joined the 4th Michigan Volunteer Infantry Regiment as a private. He rose to captain in that regiment before being appointed colonel of the 15th Michigan on March 13, 1862. He led his regiment at Shiloh and commanded the 2nd Brigade, 6th Division during the siege and battle of Corinth. He returned to command the 15th Michigan during the siege of Vicksburg where he was part of the XVI Corps. He briefly commanded the 2nd Brigade, 4th Division, XV Corps and was transferred to Chattanooga in the wake of Ulysses Grants 