Sorry, thats untrue.
There is a huge difference between remaining viable, and a population explosion that strains the very fabric of our society and its resources,
When I was in HS the population was approaching the 200 million mark.
I assume that you know what it is now?
We did not get over 150 million immigrants in that time, and I further say that this type growth of unrestrained "growth" would be more properly termed "cancer."
When I was born it was ~139 million. In 1950 ~150 million and in 1960 about ~179 million and now there is just too damn many.