While researching grave sites of Confederate Veterans in South Central Missouri I came across Samuel Thomas Williams who is buried in Heaton Cemetery in Shannon County. There is a picture of his government stone on Find-A-Grave which states "Samuel Williams, 1st Corp, Co L, 2nd Cav, 86th Reg, Confederate States Army, Sep 4 1835, Dec 18 1918" His Missouri Confederate Pension Application indicates that he was probably initially in the 2nd Infantry Regiment, 7th Division, Missouri State Guard where he fought at Wilson's Creek and Lexington and then in Company L, Fristoe's MO Cavalry where he fought at Ironton (probably Fort Davidson).

Can anyone explain the designation 2nd Cav, 86th Regt on the government stone?

Thanks