Obviously, it will depend entirely on Precisely where you are referring to:
For instance, where I come from in Victoria, Australia, they would barely have heard of baseball, and very little soccer was played here at all in those days:
Here the most popular traditional sports were cricket and Australian Football, yet just over the nearest state border, in NSW, it would have likely been cricket and rugby.
Cue sports, such as billiards and snooker also became more popular around these decades. Boxing was also a big one back in the early half of 20th Century. Martial Arts were virtually, unheard of ... basketball barely touched ... soccer only English 'die-hards' - In Australia, mainly cricket and the football codes, some tennis ... and horseracing has also always been big in Australia.
Baseball must have been one of the two. I can't guess the other.
In the US it was baseball.
Football is the most popular sport in Brazil.Soccer.The most popular sport in Brazil is football.
cricket is most popular sport
Ice hockey
no. jousting is the most popular sport.
Football is the most popular sport in Spain!:)
Football is the most popular sport in Iraq.
Venezuela's most popular sport is baseball.
Football is the most popular sport in Spain!:)
Football is the most popular school sport.
The most popular sport in El Salvador is Soccer