The National Football League (NFL) is a professional American football league consisting of 32 teams, divided equally between the National Football Conference (NFC) and the American Football Conference (AFC). The NFL is one of the four major professional sports leagues in North America, and the highest professional level of American football in the world. The NFL's 17-week regular season runs from the week after Labor Day to the week after Christmas, with each team playing sixteen games and having one bye week. Following the conclusion of the regular season, six teams from each conference (four division winners and two wild card teams) advance to the playoffs, a single-elimination tournament culminating in the Super Bowl, played between the champions of the NFC and AFC. The NFL was formed in 1920 as the American Professional Football Association (APFA) before renaming itself the National Football League for the 1923 season. The NFL agreed to merge with the American Football League (AFL) in 1966, and the first Super Bowl was held at the end of that season; the merger was completed in 1970. Today, the NFL has the highest average attendance (67,591) of any professional sports league in the world and is the most popular sports league in the United States. The Super Bowl is among the biggest club sporting events in the world and individual Super Bowl games account for many of the most watched television programs in American history, all occupying the Nielsen's Top 5 tally of the all-time most watched U.S. television broadcasts by 2015. The NFL's executive officer is the commissioner, who has broad authority in governing the league. The team with the most NFL championships is the Green Bay Packers with thirteen; the team with the most Super Bowl championships is the Pittsburgh Steelers with six. The current NFL champions are the New England Patriots, who defeated the Seattle Seahawks 28–24 in Super Bowl XLIX.

The National Hot Rod Association (NHRA) is a drag racing governing body, which sets rules in drag racing and hosts events all over the United States and Canada. With over 40,000 drivers in its rosters, the NHRA claims to be the largest motorsports sanctioning body in the world. The association was founded by Wally Parks in 1951 in California to provide a governing body to organize and promote the sport of drag racing. The first nationwide NHRA sponsored event was held in 1955, in Great Bend, Kansas. (Typical for the era, this race was held on a World War II-constructed training air field.) The NHRA Mello Yello Drag Racing Series, the national event series which comprises 24 races each year, is the premier series in drag racing that brings together the best drag racers from across North America and the world. The NHRA U.S. Nationals are now held at Lucas Oil Raceway at Indianapolis in Clermont, Indiana and are officially called the U.S. Nationals. Winners of national events are awarded a trophy statue in honor of founder Wally Parks. The trophy is commonly referred to by its nickname, a “Wally”.

Major League Baseball (MLB) is a professional baseball organization that is the oldest of the four major professional sports leagues in the United States and Canada. A total of 30 teams now play in the American League (AL) and National League (NL), with 15 teams in each league. The AL and NL operated as separate legal entities from 1901 and 1876 respectively. After cooperating but remaining legally separate entities since 1903, in 2000 the leagues merged into a single organization led by the Commissioner of Baseball.[6] The organization also oversees minor league baseball leagues, which comprise about 240 teams affiliated with the major-league clubs. With the World Baseball Softball Confederation, MLB manages the international World Baseball Classic tournament. Baseball's first professional team was founded in Cincinnati in 1869. The first few decades of professional baseball were characterized by rivalries between leagues and by players who often jumped from one team or league to another. The period before 1920 in baseball was known as the dead-ball era; players rarely hit home runs during this time. Baseball survived a conspiracy to fix the 1919 World Series, which came to be known as the Black Sox Scandal. The sport rose in popularity in the 1920s, and survived potential downturns during the Great Depression and World War II. Shortly after the war, baseball's color barrier was broken by Jackie Robinson. The 1950s and 1960s were a time of expansion for the AL and NL, then new stadiums and artificial turf surfaces began to change the game in the 1970s and 1980s. Home runs dominated the game during the 1990s, and media reports began to discuss the use of anabolic steroids among Major League players in the mid-2000s. In 2006, an investigation produced the Mitchell Report, which implicated many players in the use of performance-enhancing substances, including at least one player from each team. Today, MLB is composed of thirty teams: twenty-nine in the United States and one in Canada. Teams play 162 games each season and five teams in each league advance to a four-round postseason tournament that culminates in the World Series, a best-of-seven championship series between the two league champions that dates to 1903. Baseball broadcasts are aired throughout North America and in several other countries throughout the world. Games are aired on television, radio, and the Internet. MLB has the highest season attendance of any sports league in the world with more than 74 million spectators in 2013.