14th Pursuit Group, United States Army Air Force - Hamilton Field, California, USA, April 1942.
When production deliveries of the 144 Vanguards ordered by Sweden, began in September 1941, the U.S. government placed an embargo on exporting the aircraft to Sweden. All Vanguards were assigned the designation P-66.
Approximately 50 aircraft were retained by the USAAF and primarily used at pursuit training bases in the western U.S. and were deployed to the 14th Pursuit Group in defensive roles.