The current Major League is made up of the National League (the Senior League) and the American League (the Junior League) and dates to 1901. However, the National League began in 1871. Many other leagues attempted formation, but the American Association in 1882 was the only one to pose much of a match for the National League. Because most, if not all the American teams were sponsored by beer and whisky companies, they were often called the Beer and Whisky League.
Each year beginning in 1884, the American Association winning team approached the National League’s Champions with a proposal for a play-off between them. Nothing formal was ever in place and the rules changed each time. In 1884 the Providence Grays of the National League played the New York Metropolitans of the American Association. Each team put up $1,000 with the winner to take the $2,000 by winning 2 out of 3 games. The Grays won the first two games.
In 1885 The National League was represented by the Chicago Whitestockings (nicknamed The Chicagos) and the American Association by the Saint Louis Browns. They played 7 games for the $2,000 prize, and because of a disagreement in game 2, they split the prize and not declare a winner.
In 1886 the two teams met again, this time for the winner to take the entire gate receipts, after expenses. The Browns won in six games. It was the only time the Americans won in the 7 times the series was played. The American Association folded in 1891.
St. Louis Browns major sponsor:
The top photo of the White Stockings, aka, the Chicagos, is from 1886 and the bottom is the 1888 team. Teams normally played with 9 to 12 members, with the manager being one of the players. Pitchers often played other positions on the days they did not pitch. Sometimes a team played with fewer than nine. They were paid to play, but only when they played and not enough to get through the year; every player had to find winter work. Not until after WWII did lesser players begin to earn enough not to have to have a second job.
Comiskey managed the St. Louis Browns and played first base. He went on to buy a minor league team in Sioux City, move it to Chicago, rename it the Chicago White Sox (eventually) and became one of the major forces in the creation of the American League and of Major League Baseball.