Baseball was United States most popular sports going in 1920s. Players like Babe Ruth played an important role in making it a fan favorite sport. Ruth went on to make New York Yankees a force to reckon with in MLB.
Over 163,00,000 people attended Major League Baseball games during the 1950's. That alone would make baseball the most the most popular sport of that decade. However there is no way of estimating how many more people went to minor league and semi-pro baseball games. At that time nearly every mid to major city was represented with a baseball team.
ballparksofbaseball.com/1950-59attendance.htm
basketball
Football
Football
Canada
football
Soccer is the #1 sport in the world :)
Nebraska volleyball is a very popular spectator sport in the state.
Football (soccer)
Generally soccer is the most popular sport.
Horse races were probably the leading spectator sport in 1800, however foot races and walking races were also popular.
Croquet
The NFL and College Football are really popular sports watched in the USA. Football is the most popular spectator sport in the US.