Baseball - The Minor Leagues | Britannica

The minor leagues formed an association in 1901 to deal with the problems resulting from the lack of agreement on contract ownership, salaries, territoriality, and other issues. The current structure was created when the major leagues reached their agreement in 1903, and the minor leagues became a training ground for prospective major league players and a refuge for older players.

In 1919 Branch Rickey, then manager of the St. Louis Cardinals, devised what came to be known as the “farm system”; as the price of established players increased, the Cardinals began “growing” their own, signing hundreds of high-school boys. Other major league clubs followed suit, developing their own farm clubs that were tied into the minors. In 1949 the minor leagues were tremendously popular: 448 teams in the United States, Canada, Cuba, and Mexico played in 59 leagues with an aggregate attendance of some 39 million, about twice that of the 16 major league clubs. The minor leagues at that time were divided into six classifications, graded according to the level of playing skills: AAA (triple A), AA (double A), A (single A), B, C, and D.

Attendance eroded soon thereafter when the major leagues began broadcasting and televising their games into minor league attendance areas. By the early 1980s, after the American and National leagues had annexed 10 choice minor league territories, the number of minor league teams had been greatly reduced, and only 17 leagues remained. Attendance had dropped, and the minor league clubs generally looked to the major league parent clubs for heavy subsidization. The purpose of the minor leagues had evolved from mainly providing local entertainment to developing major league talent.

This situation improved in the early 1990s. As ticket prices for major league games escalated, attendance at less expensive minor league games rose apace. Further, development of new stadiums and renovation of existing facilities created more interest in minor league baseball. By 2009 attendance at minor league games had reached more than 41.6 million. The minors had 16 leagues with 174 teams falling into one of five classifications—AAA, AA, A (full season), A (short season), and Rookie. The minor league franchises successfully concentrated on drawing families to their parks with both games and promotional entertainment.