The Global Geocodes are designed to work at subnational levels. Here, for the United States, the nation code 5140 has added to it a two digit decimal number. Like the global codes, codes are assigned using the directional path North to South, then East to West (NSEW). U.S. Census Bureau defined regions are the base, with Maine being 5140.01. See map below.
The library function here organizes Wikipedia pages geographically. The codes can be used as well for data aggregation by region and related analyses.
The jump from Texas to Michigan may seem severe, but an analyst can handle it.
Some information is in the "Geocode Introduction" sidebar. If you are interested in more information, send me an email for the current paper and related information. Tom.Christoffel (at) gmail.com