While I don't agree that the US is "full" by any means, population density is a horrible statistic for comparison. Check this out: http://www.wolframalpha.com/

While I don't agree that the US is "full" by any means, population density is a horrible statistic for comparison. Check this out: http://www.wolframalpha.com/input/?i=population+density+of+european+union http://www.wolframalpha.com/input/?i=population+density+of+e... http://www.wolframalpha.com/input/?i=population+density+of+east+coast http://www.wolframalpha.com/input/?i=population+density+of+e... Now that's of course massaging the numbers. People/area still puts the EU ahead, ~300 vs. ~500 p/mi^2 (got this by putting "mean" in front of the above searches) but the Eastern US is not "through the floor" by comparison. It's roughly equivalent to France. Now if you lump the whole Western US in there then yeah you drop that number into the basement (Alaska is bigger than Germany+France+Spain) but if I take a big chunk of Africa or Russia and call it part of the EU then I can do the same over there, which is more-or-less the same thing from a geological, hydrological and climatic perspective.