For those who don't know, the government keeps the "personally identifiable" information from the Census secret for 72 years (at which point 97% of the people in it are dead). Which means the 1940 Census was just posted on the government's websites. While there are lots of tangents for historical researcher, of special interest to road historians is that the Census Bureau broke the country up into "enumeration districts" based on a progression of first county, then township (or its equilivant in the various states) and then sub units generally based on roads or rivers). Thus recorded on the first page of the various returns is a county map. Which in most states is just the 1939 general highway map with a few lines drawn on it to form the districts. So we have a snapshot of the road system (alignment, pavement quality, etc) as it existed them. Fun to spend a few hours looking at.
JMO.
Interesting - thanks for the information. Sometimes they'll also have city maps.
The maps can no longer be zoomed in to a reasonable level, but http://research.archives.gov/description/821491 has the same maps with good zoom.
As an aside, for Connecticut, several of the city maps have street names, but no route numbers at all. I've seen that in a few 1930s/1940s paper maps I've bought as well. It's really infuriating when that happens.
I looked at some of these maps, and there used to be a fairground in Mena, AR where KFC is now. You learn something new every day.