> I'm assuming a passport or military ID would have been adequate. I really can't emphasize enough the degree to which the US revolves around state-issued phot

> I'm assuming a passport or military ID would have been adequate. I really can't emphasize enough the degree to which the US revolves around state-issued photo IDs, whether in the form of a driver's license or a simple ID card. This assumption is baked into everything. Take a look at this page: http://www.travel.state.gov/passport/ppi/stats/stats_890.html http://www.travel.state.gov/passport/ppi/stats/stats_890.htm... In 2000, there were fewer than 50 million valid US passports. That's less than 18% of the population at the time, and a chunk of those passports were probably not truly valid -- US passports are good for 10 years, and nobody bothers to tell the State Department when somebody dies. 10 years earlier, in 1990, there were only about 11 million passports, less than 4% of the US population at the time. This is because nobody needed one. Few Americans leave the US to go anywhere other than Canada or Mexico. Until 2009, land-based travel to Canada and Mexico did not require a passport, and until 2007, air travel to Canada and Mexico didn't, either. This isn't Europe, you can't drive across multiple international borders on a day trip. It's possible to traverse over 4,400km in a straight line (on land) without leaving the 48 contiguous US states, and over 6,600km in a straight line (on land) going from northwestern Canada to southern Mexico, with only the US in between. In contrast, by the time it became common for Americans to need an ID card at all, drivers licenses were also becoming common. Win-win.