Neil, what's your source on 15th Missouri Cavalry CSA? That regiment didn't come into existance until the summer of 1864, long after Allen returned home. The 1882 History of Davies County tells us, at page 666, that George P. Allen volunteered for Gov. Jackson, was taken prisoner in 1861, was released in March 1862, and returned home. His service card at the Missouri State Archives indicates as much. That reference to Gov. Jackson and the year he was taken prisoner indicates probable service in the Missouri State Guard.