There are only four Spain men listed in the CSRs for the 6th Missouri, they consist of few cards.

Private Henderson Spain enlisted in Company A, 6th Missouri Cavalry December 18,1863 at Washington, Arkansas, last shown present on January/February 1864 muster, this appears to be the last surviving muster roll

Private Richard Spain enlisted in Company A, 6th Missouri Cavalry, September 20,1862 in Dade County, Missouri, last shown present on January/February 1864 muster

Private Robert Spain enlisted in Company A, 6th Missouri Cavalry, June 29, 1863 in Cedar County, Missouri, last shown present on January/February 1864 muster

Private W. D. Spain enlisted in Company A, 6th Missouri Cavalry, December 13, 1863 in Washington County, Arkansas, last shown present on January/February 1864 muster