In the late 1950's heading into the 1960 Olympics I believe there were no
U.S. players in the NHL.  This was in contrast to the 1940's when there
were a number of U.S. players, including hall-of-famer's.  The opinion I
read on this presented it as more an issue of attitude (on the part of
owners) and less an issue of quality of players.  For instance, John
Mayasich was on the 1960 Olympic team.  As the amateur hockey player
of the first half century in the U.S. and a nearly three point per game
scorer in college, he nonetheless was never given an opportunity to play
in the NHL.

Doug Peterson