Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. John Patrick Kerin (March 3, 1875 - March 16, 1946) was a professional baseball umpire. Kerin umpired 265 American League games from 1908 to 1910. He also umpired in the Eastern League and the Southern League from 1911 to 1920. 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.