You were right! The son of James and Elizabeth Dorsett did marry Cornelia A. McCarley, in Tippah Co MS.
Thanks for the lead. Someone researching this line can use the data.
John and Cornelia were in Madison Co ILL in 1870. Seems she named a daughter for her Mother and another for her sister? Just a guess... === I am adding census for both sides, in case anyone needs them.
1870 Madison Co, ILL Alton P.O., City of Alton John A. Dorsett 34, laborer, b NC Cornelia ", kps hse, 28, b SC Mary C. " 5, b MO Margaret 3, b MO Series:M593 Roll:252 Part:1 Page:446A === Cornelia A. McCarley, b abt 1841 Anderson Co., SC, m 12 Feb 1861 Tippah Co., MS, to a J. A. Dorsett. === Haven't checked the actual census, used the ones on the Tippah MS RootsWeb