According to this, they are right behind the Dominican with 94 and almost triple Cuba who is 4th (US is 1)
https://en.wikipedia.org/wiki/List_of_active_Major_League_Baseball_players_by_country_of_birth
The Tigers exception was that they had 2 of the biggest stars at the time. Compared to non Dominican/Puerto Rican(if you count it as “foreign “I’d be shocked if they don’t have the next most foreign players in the the majors (and especially if you include the minors)