Due to advancements in Industrialization, free time became a common norm. Because of this, people had more money and time to spend on leisure activities– such as sports– and the popularity of athletics increased.
Baseball and boxing were already professional sports prior to the 1920's, while professional football didn't even become a thing until 1920's.
Tennis, Golf, and Polo were viewed as sports for the wealthy, and only caucasian males played them.
In the 1920's, watching sports increased in popularity. Stadiums were built to allow people to be spectators for their favorite sports.
Madison Square Garden, originally a theatre, was rebuilt in 1925 to hold sports like boxing, basketball, and ice hockey.
Yankee Stadium, located in the Bronx of New York City, was built in 1923 as a ballpark for baseball. It has since been given the nickname "the house Ruth built" in reference to the famous Red Sox player Babe Ruth, who was very popular in the 1920's.
In 1921, baseball was broadcasted on radio for the first time.
Because of Jim Crow laws, Blacks and Whites were not allowed to play together.
The "New York Harlem Globe Trotters" were formed in 1927 and helped revolutionize the way people of the time viewed black people and sports, since only whites were allowed to be on professional basketball teams.
In conclusion, 1920's sports transformed athletics by adding stadiums, allowing people to listen through the radio, and changing racial views by proving all races can be athletic.