The current population for Washington D.C. is 601,723 persons
I think the context of this was that the Roman Empire started off pretty small but expanded greatly in the about 400 years the map shows
Answer: Many of them moved to Chicago to escape segregation and discrimination in the south.
Government in the 1850's tried to be fair (as fair as you can be with slavery going on) by keeping pretty much half of the country free for all people and the rest sticking with slavery
