Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. William Henry McWilliams (November 28, 1910 in Dubuque, Iowa, January 21, 1997) was a Major League Baseball player. He had two at bats for the Boston Red Sox during the 1931 baseball season. 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.