Before Google Maps, there was this enormous book with yellow, pink, green, and white pages in it, with the text printed on very thin paper. It was called "the phone book," and wrestling dudes trying to mimic Hulk used to show off by tearing them in half.
Well, the ACG, or Address Coding Guide, was the feeder into those books as created by the U.S. Census Bureau. It was a listing of essentially every street name and number in the country.
Think of it as the greatest collection of junk mailing lists in history. Google Maps and the internet changed the ease with which this data is collected, and most of this info is now readily available at the click of a mouse. Our suggestion: type in Area 51 and see what happens.
