so i just got done reading a trilogy of books by S.M Stirling about a fictional nation called "The United States of America." Its POD is where the Rebellion of the 1770s were successful and an independent state is created. In the books, however, America is depicted as somehow expanding and dominating the North American Continent in a few decades, not to mention its status as a Mary Suetopia, completely democratic and everyone is welcomed in.
So i was wondering if anyone knew how to make a more plausible version of "America." What would happen in real life if the 13 colonies broke away and became an independent nation?