In July 1863, Capt. Spencer, who was the Chief-of-Staff of Brig. Gen. Grenville M. Dodge, asked permission to be transferred to the First Alabama Cavalry which did not have a permanent commander. His request was granted and he took formal command September 11, 1863 in Corinth, MS. After the war he moved to Decatur, AL and began practicing law. He served as register in bankruptcy court and two terms as senator. His first wife, Bella Zilfa, an Englishwoman, was an author and wrote Ora, the Lost wife, in 1866 and Surface and Depth in 1867. She died in Tuscaloosa, AL in 1867 and ten years later Spencer married Mrs. Loring Nunez, niece and namesake of Maj. Gen. William W. Loring, CSA. Spencer spent some time in Nevada as a rancher and died February 19, 1893 in Washington, DC.

Buried:
Arlington National Cemetery, Arlington, Virginia