The National Association

The National Association of Professional Base Ball Players (NAPBBP), often known simply as the National Association (NA), was the first fully-professional sports league in baseball. The NA was founded in 1871 and continued through the 1875 season. It incorporated several professional clubs from the National Association of Base Ball Players (NABBP) of 1857–1870, sometimes called "the amateur Association". In turn, several NA clubs created the succeeding National League of Professional Baseball Clubs, which joined with the American League of Professional Baseball Clubs in the National Agreement of 1903, a "peace pact" that recognized each other as legitimate "major leagues". Following nearly a century of cooperation, the two leagues eventually merged into one organization in 2000 as Major League Baseball (MLB).