The 1903 World Series was the first modern World Series to be played in Major League Baseball. It matched the American League (AL) champion Boston Americans against the National League (NL) champion Pittsburgh Pirates in a best-of-nine series, with Boston prevailing five games to three, winning the last four. This was the first major professional sports championship ever won by a Boston-based team. The first three games were played in Boston, the next four in Allegheny, and the eighth (last) game in Boston. Won the 1903 World Series on October 13, 1903. Wiki link