Editing Promotion and relegation (section)

===Early baseball leagues in the United States===
In baseball, the earliest American sport to develop professional leagues, the [[National Association of Base Ball Players]] (NABBP) was established in 1857 as a national governing body for the game. In many respects, it would resemble England's [[The Football Association|Football Association]] when founded in 1863. Both espoused strict [[Amateur sports|amateurism]] in their early years and welcomed hundreds of clubs as members.

Baseball's National Association was not able to survive the onset of [[professional sport|professionalism]]. It responded to the trend – clubs secretly paying or indirectly compensating players – by establishing a "professional" class for 1869. As quickly as 1871, most of those clubs broke away and formed the [[National Association of Professional Base Ball Players]] (NAPBBP).{{efn|Both were associations ''of clubs'' despite their names.}} That new, professional Association was open at a modest fee, but it proved to be unstable. It was replaced by the [[National League (baseball)|National League of Professional Base Ball Clubs]] in 1876, which has endured to the present day. The founders of the new League judged that in order to prosper, they must make baseball's highest level of competition a franchise based system with exclusive membership, a strict limit on the number of teams, and each member having exclusive rights to their local market.{{efn|At least one economically and competitively viable incumbent was excluded, the second of three 1875 clubs in Philadelphia.}}

The modest National League guarantee of a place in the league year after year would permit the owners to monopolize fan bases in their exclusive territories and give them the confidence to invest in infrastructure, such as improved ballparks. In turn, those would guarantee the revenues to support traveling halfway across a continent for games.{{efn|For comparison, the distance between [[Boston]] and [[St. Louis]], the longest road trip in Major League Baseball before 1953, is similar to that between [[Madrid]] and [[Frankfurt]], or [[Rome]] and [[Amsterdam]].}} Indeed, after its first season, the new league banked on its still doubtful stability by expelling its members in New York and Philadelphia (the two largest cities), because they had breached agreements to visit the four western clubs at the end of the season.

The NL's dominance of baseball was challenged several times after its first few years, but only by entire leagues. Eight clubs, the established norm for a national league, was a prohibitively high threshold for a new venture. Two challengers succeeded beyond the short-term, with the National League fighting off a challenge from the [[American Association (19th century)|American Association]] after a decade (concluded 1891). In 1903 it accepted parity with the [[American League]] and the formation of the organization that would become [[Major League Baseball]]. The peace agreement between the NL and the AL did not change the "closed shop" of top-level baseball but entrenched it by including the AL in the shop. This was further confirmed by the [[Supreme Court of the United States|Supreme Court]]'s 1922 ruling in ''[[Federal Baseball Club v. National League]]'', giving MLB a legal monopoly over professional baseball in the US.

The other [[major professional sports leagues in the United States and Canada]] have followed the MLB model of a franchise based system.