The “American Heritage Dictionary of the English Language” cites the conventional wisdom that the word “southpaw” originated “from the practice in baseball of arranging the diamond with the batter facing east to avoid the afternoon sun. A left-handed pitcher facing west would therefore have his pitching arm toward the south of the diamond.” As the third edition of “The Dickson Baseball Dictionary” points out, however, that origin story is a little too simplistic. The earliest baseball mention of a “southpaw”—as found by Tom Shieber, senior curator at the National Baseball Hall of Fame—appeared in the New York Atlas in 1858, but in reference to a left-handed first baseman, not a pitcher. Boston Globe baseball writer and former ballplayer Tim Murnane also recalled in a 1908 edition of Arizona’s Bisbee Daily Review that a St. Louis newspaper had called him a “southpaw” in 1875 because he was a left-handed batter. Murnane adopted the term in describing pitchers “simply because they were left-handed, and not because they pitched the ball towards the sunny south on certain grounds.”
As Murnane pointed out, numerous big-league stadiums were not oriented with the pitcher facing west. That was not the case, though, with Chicago’s West Side Park, and it’s theorized that Chicago News sportswriter and humorist Finley Peter Dunne or the Chicago Herald’s Charles Seymour made the geographic connection by calling left-handed hurlers “southpaws” in the 1880s.
John Thorn, Major League Baseball’s official historian, told Wall Street Journal language columnist Ben Zimmer that he believes the term for lefties likely originated with a wholly different sport—boxing. In its coverage of an 1860 bare-knuckle prizefight, the New York Herald reported that left-hander David Woods “planted his ‘south paw’ under [his opponent’s] chin, laying him out as flat as a pancake” in the ninth round. Even earlier, an 1848 political cartoon depicted Whig vice presidential candidate—and future president—Millard Fillmore lying battered on the ground after being punched by the left hand of Democratic presidential candidate Lewis Cass and lamenting, “Curse the Old hoss wot a south paw he has given me!” The Whig ticket of Zachary Taylor and Fillmore, however, ultimately delivered the knockout punch at the ballot box that fall by defeating Cass for the White House.