William Aloysius McGowan (January 18, 1896 December 9, 1954) was an American umpire in Major League Baseball who worked in the American League from 1925 to 1954. McGowan founded the second umpire school in the United States. He was inducted into the National Baseball Hall of Fame in 1992. McGowan was born and grew up in Wilmington, Delaware. In 1913, he began umpiring in the Tri-State League at the age of 17. He moved on to the Virginia League in 1915, the International League and New York State League in 1916, and the Blue Ridge League in 1917. McGowan served in the United States Armed Forces during World War I in 1918, and then returned to the International League for 1919. Following the 1922 season, McGowan left the International League and joined the umpiring staff of the Southern Association, staying there until 1924. On April 14, 1925, McGowan umpired his first American League game. He umpired third base in that game.
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