Origin of the office
The title "commissioner", which is a title now applied to the heads of several other major sports leagues as well as baseball, derives from its predecessor office, the National Commission. The National Commission was the ruling body of professional baseball starting with the National Agreement of 1903, which made peace between the National League and the American League (see History of baseball in the United States). It consisted of three members: the two League presidents and a Commission chairman, whose primary responsibilities were to preside at meetings and to mediate disputes. Although the Commission chairman August Herrmann was the nominal head of major league baseball, it was AL President Ban Johnson who dominated the Commission.
The event that would eventually lead to the appointment of a single Commissioner of Baseball was the Black Sox Scandal — perhaps the worst of a series of incidents in the late 1910s that jeopardized the integrity of the game. However, the motivations behind the creation of the Commissioner's office were more than the mere desire to rebuild public relations. The scandal had not only tarnished the image of baseball, but had brought relations between team owners and AL President Johnson to a breaking point. In particular, Chicago White Sox owner Charles Comiskey was incensed at what he perceived to be Johnson's indifference to his suspicions that the 1919 World Series had been thrown. As a result, the National League, whose owners had never been on good terms with Johnson, agreed to invite the White Sox along with the Boston Red Sox and New York Yankees to join their league. The NL also unveiled plans to put a twelfth team in Detroit.
With the American League's status as a major league and possibly its very existence suddenly in jeopardy, the five AL owners loyal to Johnson sued for peace. Eventually, at the urging of Detroit Tigers owner and Johnson loyalist Frank Navin, a compromise was reached in late 1920 to reform the National Commission with a membership of non-baseball men.