So, where did all these people come from?
As part of it's very interesting "Remade in America: The Newest Immigrants and their Impact" series, the New York Times has put up a fascinating interactive map that displays the country of origin for the foreign-born population by county.
This is pretty cool in itself but the demographics fun is multiplied when you notice the slider that lets you look at the map using data from every census back to 1880. Want to see how the population of your home county has changed over the last 128 years? Just move the slider and watch the color coding shift. Want to see where people from a particular county settled, and when? Just choose one of the countries a drop-down menu and you can see what counties they settled in. Sadly the list of countries isn't very long but does cover the most common countries of origin.
A mouse-over of the county will cause the county, it's number of foreign-born residents, and total population -- all for the selected census--to be identified in a bubble.