This is a primary document for sports. This is a photo in 1920 of the North Carolina State University football team lined up for their first picture of their new season just after moving into the Southern Conference which was the biggest conference in college football at the time. They also just built their brand new stadium to go along with moving into the conference.
(http://ncpedia.org/sports/golden-age-sports)
This image is from the poster promotion of the 1921 World Series between the New York Giants and the New York Yankees.
(http://www.baseball-almanac.com/ws/yr1921ws.shtml)
During the Golden Age, sports became an all american activity between baseball and college and pro football. In 1920, the AFA (american football association) was established and it started to compete with baseball for national attention. Some of the major teams like the New York Giants, Chicago Bears, Dallas Cowboys, and many other that molded the new shape of sports in the USA. This lead to national heroes such as Babe Ruth and Ty Cobb emerging in sports to attract attention to their sports. Just like the roman times, people love fighting and contact to achieve a goal. This is very similar to football which is all about hitting people to run to the end zone. Also during this time, hockey was organized into the NHL and became the third national sport. With the mass use of radios, baseball games could be broadcasted and sports spread their influence across the globe. Jack Dempsey led the way for boxing in the 1920s and reigned as the world heavyweight champion from 1919 to 1926. Bobby Jones raised attention to golf by co-founding the Masters and creating the Augusta National Golf Club. He also spread his wisdom with other golfers in his golf books. The king of tennis, Bill Tilden, was ranked number 1 in the world for 6 years and recorded 10 major championships (singles).
This video is a boxing match between Tunney vs Gibbons in an all out battle for the century.