Baseball in the United States

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Baseball in the United States
Fenway Park in Boston is the oldest ballpark in Major League Baseball.
Country	United States
Governing body	USA Baseball
National team(s)	Men's national team; Women's national team
First played	1862
National competitions
World Series Triple-A National Championship Game
Club competitions
Major League Baseball (Major league) International League (AAA) Pacific Coast League (AAA) Eastern League (AA) Southern League (AA) Texas League (AA) Midwest League (A+) Northwest League (A+) South Atlantic League (A+) California League (A) Carolina League (A) Florida State League (A)
International competitions
Summer Olympics WBSC Premier12 World Baseball Classic Women's Baseball World Cup U-23 Baseball World Cup U-18 Baseball World Cup U-15 Baseball World Cup U-12 Baseball World Cup

Major League Baseball (MLB) is the highest level of baseball in the United States.^[1] Baseball is one of the most popular sports in the U.S. for both participants and spectators.^[2][3]

MLB's World Series is the culmination of professional American baseball's postseason each October. It is played between the winners of MLB's two leagues, the American League (AL) and the National League (NL). Prior to the World Series, the winner of each league is determined in a best-of-seven playoff called the League Championship Series (LCS), in which one team in each league comes away with their league's pennant; the winner of the American League Championship Series (ALCS) receives the American League Pennant, and the winner of the National League Championship Series (NLCS) receives the National League Pennant. Six teams from each league compete in the postseason. After a champion is crowned from each league, the winner of the World Series is determined through a best-of-seven playoff.^[4][5]

As baseball developed over 150 years ago in the Northeastern United States, it has been played and followed in the region longer than any other sport in the nation. As of 2022, the Philadelphia Phillies, founded in 1883, are the oldest continuous same-name, same-city franchise in both Major League Baseball and all professional sports in the United States and Canada.^[6]

An extensive minor league baseball system covers most mid-sized cities in the United States. Minor league baseball teams are organized in a six-tier hierarchy, in which the highest teams (AAA) are in major cities that do not have a major league team but often have a major team in another sport, and each level occupies progressively smaller cities. The lowest levels of professional baseball serve primarily as development systems for the sport's most inexperienced prospects, with the absolute bottom, the rookie leagues, occupying the major league squads' spring training complexes and making no effort to earn money on their own.

The World Baseball Classic, the most popular international baseball tournament for national teams, is held every four years in March.^[7] USA's national baseball team won its first championship in 2017, and lost to Japan in 2023's championship game, earning second place.

Some limited independent professional baseball leagues exist in the United States, the most prominent being the Atlantic League, which occupies mostly suburban locales that are not eligible for high level minor league teams of their own. Outside the minor leagues are collegiate summer baseball leagues, which occupy towns even smaller than those at the lower end of minor league baseball and typically cannot support professional sports. Summer baseball is an amateur exercise and uses players that choose not to play for payment in order to remain eligible to play college baseball for their respective universities in the spring. Collegiate summer baseball also gives athletes the opportunity to be scouted by MLB teams.

At the absolute lowest end of the organized baseball system is senior amateur baseball (also known as Town Team Baseball), which typically plays its games only on weekends.