No one is exactly sure how baseball started but it was inspired by the English game “rounders”. Rounders had many of the same rules as baseball in the present day. One difference was you could throw the ball at the runner, to tag out the runner. Baseball took over as the United States`s most popular sport. The early baseball teams were mostly based out of New York and Brooklyn. The first professional team was the Cincinnati Red stockings. More teams wanted to be like the Stockings so then the MLB was born.