Assertion: inning | /r/HasProperty | its integration
Facets:
value: with the national league
type: OTHER
Source sentences:
text: This inning covers approximately 1900 to 1910, and includes the formation of the American League and its integration with the National League, culminating in the establishment of the World Series, as well as the emergence of the game's first great star, Christy Mathewson, which helps to clean up baseball's image as a rowdy, brawling game.