UPDATED TO MUCH MORE DETAILED QUESTION
I'm building a set of geofences to be installed on a GPS unit to track vehicles as they cross state lines. The list of geofences are simple latitude/longitude pairs, but each geofence needs to be a single polygon. The problem I'm having is that all datasets I find include a polygon for EVERY body of land (so every island off of Maine gets its own geofence).
Notice how Massachusetts is a single geofence, as is Rhode Island and Connecticut. Including water in the geofence is fine.
I know this isn't possible for some states due to the Kentucky Bend, but I don't know if there are other exclaves (or enclaves) in the United States. In the case of Kentucky, I could simply have a Kentucky_Geofence_1 and Kentucky_Geofence_2, whereas I'd only need 1 for each of the three green states illustrated above.
As long as there's a way to export the data from a given format to JSON, XML, CSV, etc, I don't care what the file format is. I'm also not opposed to buying it, if it's already out there.
(These images come from a custom Google Map I've been tweaking manually by dragging-and-dropping pins to manually create these, but it's going to take a LONG time to do them all, and it seems like this must have been done somewhere else already....)