Note I said "populated". True there were settlements in the south but until the last 50 years all the big population centers and manufacturing was in the northeast.
Compare the list of the biggest cities in 1950 with today- http://en.wikipedia.org/wiki/Largest_cities_in_the_United_States_by_population_by_decade
9 of the 10 biggest cities were in the northeast in 1950- today- only three are- the rest are in the south and southwest. . . . . .