Baseball's first openly all-professional team was founded in Cincinnati in 1869. (There had been teams in the past that paid some players, and some that had paid all players but under the table.) The first few decades of professional baseball were characterized by rivalries between leagues and by players who often jumped from one team or league to another.

Baseball broadcasts are aired on television, radio, and the Internet throughout North America and in several other countries throughout the world. MLB has the highest season attendance of any sports league in the world with more than 73 million spectators in 2015 (a statistic inflated by the amount of games per season).

According to wikipedia