Jackie Robinsonwas interested in join the Major League Baseball
The first season of the Seattle Mariners was 1977.
It would be very hard for another entity to join Major League Baseball now that sports organizations are considering dropping teams.
Jackie Robinson made his Major League debut with the Brooklyn Dodgers on April 15, 1947.
The Major League Baseball (MLB) team known as the Houston Astros originated in the MLB National League (NL) in 1962 as the Houston Colt 45's, changing their name to the Houston Astros in 1965.
It is not mandatory, but it definitely increases your chances of getting noticed by scouts.
They joined at the end of the season in 1997 but didn't play until 1998.
League of Nations.
The United States