Missouri State Archives rolls show Joseph Wells was a private in Company D, Andrew County Battalion EMM, age 33. Enrolled April 23, 1864 at Savannah, Mo., mustered in April 30, 1864.
You might also find it of interest that on those same dates in that same company, Pvt. George Wells, age 25, and Pvt. P.H. Wells, age 39, also enrolled at the same location.