The large increase in the number of births from 1946-1961 is known as the

"Baby Boom" thus creating the "Baby Boomers" generation, as post-WWII populations rose exponentially. 

I believe it was called  the "Baby Boom".

Hope this helps you! :)

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.