Immigration levels in the 50's were at least as high as today. Yes they were white - because they came from Europe. And many of them were unskilled and many were unable to speak English. But, just as todays immigrants do, the majority worked hard and managed to improve themselves.
In the Seventies, nearly 75% of immigrants had a high school education or less. Now, over 50% have college or university. Also, the large majority of immigrants make the same money as everybody else. In 2005 the median family income for non-immigrants in Ottawa was about $85,000, versus $70,000 for immigrants. Less, but hardly 'minimum wage'.
Source: http://www.canadaimmigrants.com/statistics.asp and http://www.canadaimmigrants.com/statistics2.asp