There are 13 U.S. states that share an international land border. The original list contained several errors (Colorado, Ohio, Pennsylvania, Utah do not border a foreign country). Here is the accurate list:
Note: Ohio and Pennsylvania border Lake Erie but have no land border with Canada. Michigan has water boundaries with Ontario.
Florida (Cuba, Bahamas), Hawaii (no land borders), and U.S. territories (Puerto Rico, USVI, Guam, etc.) have maritime boundaries but no land borders.