I don't know why I find geographic entities like U.S. Zipcodes and Counties so fascinating, but I obviously do and my latest project has been Counties. Did you know there are 3,142 official counties in the U.S.? Each one has a unique five digit code consisting of a two digit state code and a three digit county code, known as FIPS codes (Federal Information Processing Standard). The state numbers range from 01 (Alabama) to 56 (Wyoming) and each county within a state has a three digit code. Thus, the FIPS code for my county here in Tennessee is 47-099.

My source for this project was a huge geojson file with all of the county polygons packed inside and it was way too big to handle with normal PHP functions so I had to tear it apart with some mad code hacking into 3142 individual county files. That was successful and I now have high quality polygons for every county.

Drop on into my newest tool Counties By State and look around if you like. Once you select a state you can view the individual counties by clicking on the code or select View Polygons to show them all. If showing all you can hover over them for a name or click on a county to bring it up individually.

I'm still working on Alaska, damned state with all it's multi-polygons is driving me crazy :-)