The traditional national sport (national pastime) of the United States is:

Baseball is traditionally regarded as the "national pastime" and national sport of the United States.

About baseball:

• It is a bat-and-ball game played between two teams of nine players each.
• The teams take turns batting and fielding; a game is normally divided into nine "innings".
• A run is scored when a batter hits the ball and runs around four bases ("first base", "second base", "third base" and "home plate") arranged in a diamond shape.
• It developed from older English bat-and-ball games such as "rounders" and cricket.
• The modern rules are often credited to Alexander Cartwright and the Knickerbocker Base Ball Club of New York (1845).
• The first recorded game under these rules was played in 1846 at Hoboken, New Jersey.
• A popular legend says that Abner Doubleday invented baseball in Cooperstown, New York, in 1839, but historians do not accept this.
• The National Baseball Hall of Fame and Museum is located in Cooperstown, New York.

Professional baseball:

• "Major League Baseball" (MLB) is made up of the National League (1876) and the American League (1901), with 30 teams.
• The championship series is called the "World Series", played since 1903.
• Famous players include Babe Ruth, Jackie Robinson (the first African-American player in the modern major leagues, 1947), Hank Aaron and the Japanese star Shohei Ohtani.

Baseball in the Olympics:

It was an Olympic sport from 1992 to 2008, and in 2020 (Tokyo). It will return at the 2028 Los Angeles Olympics.

Baseball is also very popular in Japan, South Korea, Taiwan, Cuba, the Dominican Republic and Venezuela.

Other popular American sports:

American football: the National Football League (NFL); its championship is the "Super Bowl". It is now the most-watched sport in the USA.

Basketball: invented in 1891 by James Naismith at Springfield, Massachusetts; the National Basketball Association (NBA).

Ice hockey: the National Hockey League (NHL).

The USA has no officially legislated national sport; baseball is traditionally recognised as the "national pastime".

Other national sports:

• Canada: Ice hockey and lacrosse (by law, 1994).
• England: Cricket (traditionally).
• Japan: Sumo.

Why not the other options?

• ✗American football is now the most popular spectator sport, but baseball is called the "national pastime".
• ✗Basketball was invented in the USA, but it is not called the national pastime.
• ✗Ice hockey is Canada's national winter sport.