From The Truth About Guns:

To be clear, there are 1,930 counties that have now become Second Amendment sanctuaries, which is more than 61% of all the counties in the United States.

Of these counties, 1,137 made the decision to protect the Second Amendment on their own. The rest are located in the 15 states — the most recent being Texas — that declared themselves Second Amendment sanctuaries, according to Noah Davis of sanctuarycounties.com and its companion site constitutionalsanctuaries.com.