[familyop]

"People forget our borders were closed from 1929 to the mid-sixties if I remember correctly."

The northern border was not closed. It was far more open than it is now.

[TheThirdRuffian]

“The northern border was not closed. It was far more open than it is now.”

Immigration-wise. Try not to be so literal.

There were a series of laws regarding this, most notable:

http://en.wikipedia.org/wiki/Immigration_and_Nationality_Act_of_1952