During the early 1900s, large numbers of african americans from the south found better job opportunities in?

Northern factory job opportunities in urban areas provided greater opportunities and wages than plantation work in the south. One example of this was the Harlem Renaissance of the 1920's in NYC. Due to the large influx of African Americans into the city and the prosperity many gained in return, there came a cultural explosion in the Harlem area. :) 

Of course, "prosperity" is a relative term. The vast majority were still poor, just better off than before.

The answer is eastern europe