National Association of Professional Base Ball Players (1871-1875), regarded by baseball historians as the first professional baseball league.

After the 1870 season, the Union refused to enter the National Association of Professional Base Ball Players(which was created by the new fifteen pro teams).

The National Association of Professional Base Ball Players was the first professional baseball organization.

The first attempt at forming a "major league" produced the National Association of Professional Base Ball Players, which lasted from 1871 to 1875.

The National Association of Professional Base Ball Players operated from 1871 through 1875, and is considered by some to have been the first major league.

It is called the Brotherhood of Professional Base Ball Players.

As a result, in 1871 most of the leading professional clubs broke away to found the National Association of Professional Base Ball Players.

They joined the first professional league, the National Association of Professional Base Ball Players, for its 1871 to 1875 duration.

The National Association of Professional Base Ball Players was formed in 1871.

He was also an active players' union member, and was elected vice president of the Brotherhood of Professional Base Ball Players.

National Association of Professional Base Ball Players (1871-1875), regarded by baseball historians as the first professional baseball league.

After the 1870 season, the Union refused to enter the National Association of Professional Base Ball Players(which was created by the new fifteen pro teams).

The National Association of Professional Base Ball Players was the first professional baseball organization.

The first attempt at forming a "major league" produced the National Association of Professional Base Ball Players, which lasted from 1871 to 1875.

The National Association of Professional Base Ball Players operated from 1871 through 1875, and is considered by some to have been the first major league.

It is called the Brotherhood of Professional Base Ball Players.

As a result, in 1871 most of the leading professional clubs broke away to found the National Association of Professional Base Ball Players.

They joined the first professional league, the National Association of Professional Base Ball Players, for its 1871 to 1875 duration.

The National Association of Professional Base Ball Players was formed in 1871.

He was also an active players' union member, and was elected vice president of the Brotherhood of Professional Base Ball Players.