FIPS state code
From Academic Kids
A two-digit Federal Information Processing Standard (FIPS) code (FIPS 5-2) uniquely identifies a state, territory, or commonwealth within or of the U.S.. These codes are used by the U.S. Census Bureau, by the Department of Agriculture to form milk-processing plant numbers, and in the Emergency Alert System, and were assigned by NIST. Additional numbers used with the EAS for territorial waters of the U.S. were assigned by the FCC, but are not part of the FIPS standard. Two-letter state codes were assigned as postal abbreviations by the USPS.