Long before President Trump turned a protectionist eye to the iniquities of Canadians, another opinionated American tycoon decided that he had had enough. Eighty years ago, the cross-border irritant wasn’t Nafta or softwood lumber. As Maj. Frederic McLaughlin saw it, Canada was flooding American markets with too many hockey players.
https://www.nytimes.com/2017/06/11/s...n-players.html