i'd like to see this against a graph for something else. i'm not informed enough to know what else could go with it. maybe...average salary or rate of insurance coverage or something. i dunno. I AM DONE WITH THINKING FOR THE DAY. ICE CREAM
I didn't realise that the eastern half of North America was so much more densely populated than the western half. Why is that?
My guess is it's just because historically most Americans immigrated from Europe and so they mostly just settled on the east coast, and they've been trickling across ever since. I'd be interested to find out, anyway.
Hopefully I'm not explaining this to another American, but the parts that are less densely populated (i.e. the Great Plains, Mojave Desert, Rocky Mountains) are that way--with the exception of the Great Plains--because their climes are not particularly suited for human life. The Great Plains were once more densely populated during the 19th century, but the Dust Bowl and agricultural overproduction forced a lot of people back to the respective coasts.
There's not much trickling going on. Most of the people who are out west are there out of sheer obstinacy or complacency and have been there a very long time.