National Association of Professional Base Ball Players

In 1869, the previously amateur National Association of Base Ball Players, in response to concerns that some teams were paying players, established a professional category. The Cincinnati Red Stockings were the first team to declare their desire to become fully professional. Other teams quickly followed suit. By 1871, several clubs, wanting to separate fully from the amateur association, broke away to found the National Association of Professional Base Ball Players. (The remaining amateur clubs founded the National Association of Amateur Base Ball Players, which only lasted two years). In 1876, wanting an even stronger central organization, six clubs from the NA and two independents established the National League: Boston Red Stockings, Hartford, Mutual, Athletic, Chicago, and the St. Louis Brown Stockings from the NA plus independent clubs Louisville and Cincinnati.

Several factors limited the lifespan of the National Association including dominance by a single team (Boston) for most of the league's existence, instability of franchises as several were placed in cities too small to financially support professional baseball, lack of central authority, and suspicions of the influence of gamblers.

Professional baseball clubs in the 19th century were often known by what is now regarded as a "nickname", although it was actually the club's name. This was a practice carried over from the amateur days. The singular form of a "nickname" was often the team name itself, with its base city "understood" and was so listed in the standings; for example the Atlantic Base Ball Club, which was located in Brooklyn. Rather than "Brooklyn Atlantics", the team was simply called "Atlantic", or "Atlantic of Brooklyn" if deemed necessary by the writer. Another common practice was to refer to the team in the plural, hence the "Bostons" the "Chicagos" or the "Mutuals". Frequently sportswriters would apply a creative pseudonym to call the team by in newspaper articles, often using one with something to do with the team colors, such as the Red Stockings or Red Caps (Boston), White Stockings (Chicago), Green Stockings (Mutual of New York), and Canaries (the yellow-uniformed Lord Baltimore).

This practice of using the singular form of the "nickname" as the team name faded with time, although as recently as the early 1900s the team generally known as "Philadelphia Athletics" was shown in the American League standings as the traditional way of "Athletic". That team sported an old-English "A" on its jerseys, as had its nominative predecessors.

Later, the Encyclopedia of Baseball attempted to retrofit the names into a modern context. In the following list, the bold names are the names most often used by contemporary newspapers in league standings, and the linked names after them are those typically ascribed to the teams now, using the Encyclopedia of Baseball standard.[8]

• Boston – Boston Red Stockings (1871–1875)
• Chicago – Chicago White Stockings (1871, 1874–1875)
• Forest City – Cleveland Forest Citys (1871–1872)
• Kekionga – Fort Wayne Kekiongas (1871)
• Mutual – New York Mutuals (1871–1875)
• Athletic – Philadelphia Athletics (1871–1875)
• Forest City – Rockford Forest Citys (1871) (A second league club with the same name as the Cleveland entry)
• Troy or Union – Troy Haymakers (1871–1872)
• Olympic – Washington Olympics (1871–1872; 1875)
• Atlantic – Brooklyn Atlantics (1872–1875)
• Eckford – Brooklyn Eckfords (1872)
• Lord Baltimore – Baltimore Canaries (1872–1874)
• Mansfield – Middletown Mansfields (1872)
• National – Washington Nationals (1872; 1875) Washington Blue Legs (1873)
• Maryland – Baltimore Marylands (1873) (played at Madison Avenue Grounds)
• Philadelphia – Philadelphia White Stockings (1873–1875) (also sometimes called "Pearls" or "Phillies")
• Resolute – Elizabeth Resolutes (1873)
• Hartford – Hartford Dark Blues (1874–1875)
• Centennial – Philadelphia Centennials (1875)
• Elm City – New Haven Elm Citys (1875)
• St. Louis – St. Louis Brown Stockings (1875)
• St. Louis Reds – St. Louis Red Stockings (1875) (this club's jerseys featured an actual image of a red stocking, making this an "official" name).
• Western – Keokuk Westerns (1875)

Before 1883, team order in baseball standings was determined by the number of games a team won, not by winning percentage. For each of the five NA seasons, the league champion had both the most games won and the best winning percentage. The placement of other clubs may vary—for example, the 1872 Philadelphia Athletics finished in fourth place (based on their win total), while recording the second-best winning percentage. The NA did not have a postseason; champions were determined by final standings at the end of the season.

† Individual statistics from tie games count towards players' career totals, but tie games are excluded when computing winning percentage and games behind.

• James W. Kerns 1871
• Robert V. Ferguson 1872–1875

Eight people who played in the NA have been inducted into the National Baseball Hall of Fame:

George Wright was the first NA inductee (1937) and Deacon White is the most recent (2013). Four of the eight had significant playing careers in the National League or other major leagues after their time in the NA: Anson, Galvin, O'Rourke, and White, each of whom was inducted into the Hall of Fame as a player.[14][15][16][17] The other four—Cummings, Spalding, and brothers George and Harry Wright—were each inducted into the Hall as an "executive", a Hall of Fame category that includes pioneers of the game.[18][19][20][21] Cummings is notable for being the pitcher credited with inventing the curveball.[22]

• David Pietrusza Major Leagues: The Formation, Sometimes Absorption and Mostly Inevitable Demise of 18 Professional Baseball Organizations, 1871 to Present Jefferson (NC): McFarland & Company, 1991. ISBN 0-89950-590-2
• William J. Ryczek Blackguards and Red Stockings: A History of Baseball's National Association Jefferson (NC): McFarland & Company, 1999. ISBN 978-0-9673718-0-1

• "First National Association Game". Retrosheet. Retrieved July 28, 2020.