The New York Times must be the place to be if you're a GIS specialist because the Times seems to have at least one new, amazing map a week. Yesterday they delivered the very usable Immigration Explorer - a web map that gives us census data going back to 1880 by U.S. county. The mapping was done with the aid of the Social Explorer, U.S. Census Bureau data.
This is a brief silent video that I made showing the use of the web map at Immigration Explorer. I did not make the map, I just used the Times' web site to make this video!
I think that the article linked to this map is here, but it seems perhaps that the Times is going to be discussing immigration in the future.
Thanks to my colleague Yu Zhou and Dave Tewksbury at Hamilton College for emailing about the map site.