This is the Internet map a few months after I first got on from Harv-10 in 1972: http://www.flickr.com/photos/walkingsf/7257339850/lightbox/ . Brings back great memories of sitting by the Harvard IMP (router) late at night, and getting a call from BBN on the phone asking me (anyone) to reboot it manually...
By the way, I (as non-US) wonder why west coast and california had more nodes even back then? I mean, west coast is less populated and if you look at night lights map it's practically invisible compared to east coast. Why tech tend to be there anyway?
Note this is just a small theory and in no way has any evidence to back it.