Answer: CLEMENS

AnswerCrossword Clue
CLEMENSReal name in literature.
CLEMENSSeven-time Cy Young Award winner of the 1980s-2000s
CLEMENSAmerican League MVP after Mattingly
CLEMENSTwain, really
CLEMENSSamuel Langhorne ...
CLEMENSOnly starting pitcher since 1971 to win a league M.V.P. award
CLEMENSAuthor Samuel
CLEMENSWriter from Hannibal, Mo.
CLEMENSTwain's original surname
CLEMENSRenowned Missourian
CLEMENSU.S. writer and lecturer
CLEMENSMark Twain
CLEMENSTwain, at birth
CLEMENSUser of a famous pseudonym.
CLEMENSMark Twain.
CLEMENSSamuel Langhorne ....
CLEMENSAn Innocent Abroad.
CLEMENSPitcher Roger named in the Mitchell report
CLEMENSGeneral Grant's publisher
CLEMENSU.S. Grant's publisher
CLEMENSBaseball's "Rocket"
CLEMENSTwain's birth name
CLEMENSTwain, actually