Raynor enlisted in the 1st Ohio Volunteer Infantry at the start of the Civil War and was commissioned as a 1st Lieutenant. At the first Battle of Bull Run in July 1861 he was taken prisoner and sent to Libbey Prison in Richmond, Virginia. He escaped after seventeen days but was spotted by a southern soldier who was going to shoot him, but according to Raynor, when the soldier saw his Masonic pin, he allowed him to escape.

 

After he reached home, he organized the 56th Ohio Volunteer Infantry and was made it's Colonel and commander on April 2, 1863. He was wounded at Snaggy Point Red River Landing near Vicksburg on May 5, 1864. He was then decorated for bravery and was discharged on October 27, 1864. He was brevetted Brigadier General, US Volunteers on March 13, 1865 for "distinguished and gallant services".

 

Raynor became a manufacturer in Toledo after the war.