Although the cities did gradually fill up with immigrants, the level of labour unrest in Canada never approached what it did in the U.S. due to the lack of industry. What did ferment couldn't be easily blamed on immigrants (Yankee organizers on the other hand were a great scapegoat), as their numbers weren't sufficient to be a threat. Policies that restricted immigration heavily in favour of people from the British Isles, and a desperate need for population growth would have made it counterproductive anyway.
Visible minorities were kept to a minimum because of draconian head tax laws that required Asians and Indians pay for each member of their family brought over so they never appeared to be a "problem." Therefore, Canada never really experienced the influx of immigration that the United States did until after World War II.
Even then, it was often a matter of the government actively searching to fill a void in our labour market. For the building of the St. Lawrence Seaway, the Toronto Subway System, and the rest of the construction boom of the 1950s, the country needed a fast influx of skilled labourers. Since Canada was doing the soliciting, and not the other way around, there was never going to be a question of demonizing the immigrant. With worker's rights firmly entrenched, there wasn't any reason to.
Through the 1960s it was easy to portray Canada as a happy, multicultural paradise without having to do anything but leave people alone. Slavery had been abolished in Canada long before it had in the United States, meaning we never had the civil rights battles here that divided America. We had safely stowed our Natives on reservations that kept them out of sight and mind, and bigotry was polite and British; it never showed on the surface because it wasn't proper. All that would change in the 1970s because of events in the outside world.