Major Sports Leagues in the US
NFL
Formed in 1920, the National Football League has a religious following in the US and around the world. It's one of the most profitable leagues in the whole world. The NFL consists of 32 teams, which are sub-divided into NFC and AFC, which compete against each other every year to win the Super Bowl, the halftime show of which features major hit musicians.
NBA
Initially formed in 1946 as the BAA (Basketball Association of America), it merged (合并) with National Basketball League in 1949 and changed its name to NBA. The National Basketball Association might not be the biggest sports league financially, but it has a larger international following than other leagues. The keyword "NBA" was among the most googled keywords in 2021, which indicates how popular it is in the world.
MLB
Baseball is considered to be the national pastime activity of the US and the Major League Baseball is its highest level in the country. The MLB might not be popular as NFL in other parts of the world, but international supporters still make a large portion of the total fanbase. Formed in 1903, the MLB is the oldest US sports league and now has 30 teams, which was a merger between the National League and the American League.
NHL
Founded in 1917, the National Hockey League is the second-oldest sports league in the US and Canada and consists of a total of 32 teams. Three of the best performing teams from each division make it to the playoffs plus two wild card teams. All teams compete to win the prestigious Stanley Cup. Most of NHL's revenue comes from TV and gate receipts with hockey-crazed Canadians being the primary market.