Richard attended the Old Masonic College at Lexington until he was 17 years old. After school he worked a year as a deputy clerk and court recorder and then the American Civil War began. He joined the Confederate Army as a private in the 8th Division, under command of Brigadier general James S. Rains, in Lt. Col John Bowman's 2nd Infantry regiment of the Missouri State Guards. Private Keith fought in the Battle of Lexington, Battle of Wilson's Creek, and the Battle of Pea Ridge. He then went to Memphis, joined the Landis battery (John C. Landis) of Missouri and fought in the 1st and 2nd Battle of Corinth, the battles of Iuka, Hatchie River, Grand Gulf, Fort Gibson,