Baseball and immigration
From Conservapedia
About 28% of major league baseball players are foreign-born, which is a far higher percentage than a generation ago, and a higher percentage than in professional football and basketball.
The best players in Major League Baseball are American-born. In 2015, for example, all six out of the six top award recipients were born as American citizens. So why is such a high percentage of the teams foreign-born?
Owners may prefer recruiting foreigners to play in the United States for the same reason that big corporations prefer foreign-born engineers: the visa system makes it easier to control foreign-born labor compared with American citizens.