There was a time that the National and American Leagues were referred to as the Senior and Junior circuit respectively.
The National League goes back to 1876 when the game had such stars as Cap Anson and Al Spaulding. The latter would go on to found Spaulding Sports Equipment.
In that inaugural year of the National League, Spaulding started on the mound 60 of the 66 games the Chicago White Stockings played (The White Stockings eventually evolved into the Cubs). Some have feciciously said that maybe he pitched every game because they were playing with his ball. It took some years for the game to evolve into the game we know today but I'm sure it wasn't that primative.
The American League came into being in 1901, 25 years after the National League, hence the Senior and Junior circuit nicknames. The first half of the 20th century, many cities had 2 baseball teams and it would be unheard of to be fans of both.
Apparently it was said a fan of a National League team and a fan of an American League team would have nothing to talk about. A genuine love of the game would not be enough. To this day if you are a Cubs fan you HATE the White Sox and vice versa.
Some American League fans have a belief that baseball didn't really begin until the American League began. As a child in New England that was my understanding as well. It was not until July 27th 1986 that the myth was actually challenged.
On that day, Don Sutton of the California Angels faced Tom Seaver of the Red Sox. It was the first matchup of two 300 game winners since.....1892????? WHAT?????
That's right, not only was there baseball in 1892 but there were pitchers who had won 300 games by that time. Upon mentioning this to my father, he was adament there was no baseball then and I got the vibe that any further discussion would be considered blasphemy. I realized though that my father did not know more than sportswriters.
The National League fan though appears very aware of baseball's origins and why they are far more protective of the game. The biggest example is not adopting the DH and I hope they never do (For more on that see my 3/20/11 post Unbalanced Schedule DH and Interleague Play)
One more myth to dispel. I apologize to any Cinncinatti fans out there but the current Reds are not decended from the first professional team from 1869 the Cinncinatti Red Stockings. That team lasted one year and owner Harry Wright disbanded the team and along with his brother George moved to Boston and named their new team the Red Stockings. That team evolved into the Braves.
And no I am not saying that baseball was invented in Atlanta by the inventors of the airplane.