Interstate System, 1816-2004

These data sets identify states, their standard Correlates of War "country code" or state number (used throughout the Correlates of War project data sets), state abbreviations, and dates of membership as states and major powers in the internationaly system. Version 2004.1 extends the temporal domain of the collection to 2004.

Users note: The order of variables in this file has changed from the 2002 version. The variables were incorrectly ordered in the 2002 version of this data set, and did not match the documentation (the first two variables were switched). In the 2004 version, variables are now in the correct order, and are identical between the "states" and "majors" data sets.