This is one of the most amazing maps I've ever seen.
Check it out here.
It's U.S. immigration since 1880. Check out different decades. Check out different countries of origin. Alter the bubble sizes. Have fun. Comment, please.
Also, for a visual of World War II - If Maps Could Fight take a look here. A playful twist on war - how creative is that?!? (yes, in a sick way, but creative nonetheless)