Southpaw (1880, 1886)

[Bapopik at AOL.COM]

   ProQuest Historical Newspapers (NY TIMES, LA Times, Washington Post) didn't turn up anything early.  I expect the Chicago Tribune to have an early citation; "southpaw" was supposed coined by the Chicago Record.
  It's interesting that the NATIONAL POLICE GAZETTE (which covered baseball) doesn't have earlier than 1886.


(AMERICAN PERIODICAL SERIES ONLINE)
      Game Bag and Gun.
              Forest and Stream; A Journal of Outdoor Life, Travel, Nature Study, Shooting, Fishing, Yachting (1873-1930).       New York: Nov 18, 1880.       Vol. Vol. 15., Iss. No. 16.;             p. 309 (1 page) :
   The club have erected a substantial club-house, and, 17th inst., Al. Heritage (jolly old "South Paw") and Capt. Johnson ("Ye Ancient Mariner"), committee, will ship by Old Dominion Line fifteen cots and mattresses,...


      Article 6 -- No Title
              The National Police Gazette (1845-1906).       New York: Jun 19, 1886.       Vol. VOLUME XLVIII, Iss. No. 457.;             p. 14 (1 page), col. 1:
   All the big sluggers of the League are Southpaws.