The National Association of Professional Baseball Players, or simply the National Association, was founded in 1871 and lasted through the 1875 season, after which its stronger teams created the National League. It is regarded as baseball's first professional league.

National Association Franchises

• Boston Red Stockings (1871-1875)
• Chicago White Stockings (1871; 1874-1875)
• Cleveland Forest Cities (1871-1872)
• Fort Wayne Kekiongas (1871)
• New York Mutuals (1871-1875)
• Philadelphia Athletics (1871-1875)
• Rockford Forest Citys (1871)
• Troy Haymakers (1871-1872)
• Washington Olympics (1871-1872)
• Brooklyn Atlantics (1872-1875)
• Brooklyn Eckfords (1872)
• Baltimore Lord Baltimores (1872-1874)
• Middletown Mansfields (1872)
• Washington Nationals (1872-1873; 1875)
• Baltimore Marylands (1873)
• Philadelphia White Stockings (1873)/Philadelphia Pearls (1874)/Philadelphia Phillies (1875)
• Elizabeth Resolutes (1873)
• Hartford Dark Blues (1874-1875)
• Philadelphia Centennials (1875)
• New Haven Elm Citys (1875)
• St. Louis Brown Stockings (1875)
• St. Louis Red Stockings (1875)
• Keokuk Westerns (1875)

Timeline

1876 - Boston Red Stockings, Chicago White Stockings, New York Mutuals, Hartford Dark Blues, and St. Louis Brown Stockings all joined the newly founded National League.

Champions

• 1871 Philadelphia Athletics
• 1872 Boston Red Stockings
• 1873 Boston Red Stockings
• 1874 Boston Red Stockings
• 1875 Boston Red Stockings

NA Presidents

• James W. Kerns 1871
• Robert W. Ferguson 1872-1875