[the_mad_monk]

Per this link:

While what we know as Major League Baseball didn’t quite begin one hundred and fifty years ago, the first professional ballclub did – the Cincinnati Red Stockings, which eventually paved the way for organized professional baseball leagues to begin in the 1870s, the current National League played their first season in 1876. The American League started up in 1901 with the two participating in the first World Series two years later in 1903.