Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. John Barrett was an American professional left fielder for the 1872 Brooklyn Atlantics of the National Association. He played in eight games from September 18 to October 31, seven of which were in left field, and gathered seven hits in 34 at bats for a .206 batting average. Major League Baseball (MLB) is the highest level of professional baseball in the United States and Canada, consisting of teams that play in the National League and the American League. The two leagues merged in 2000 into a single MLB organization led by the Commissioner of Baseball after 100 years as separate legal entities.