In 1996, I was hired to liquidate the estate of a 'mad scientist' in San Diego. I found photographs of an ME 262 being reverse engineered at San Bernardino Air Materials Command (which later became Norton AFB). The photos were dated June, 1944. By then Norton AFB was shut down, and I couldn't find anyone who knew about it.
"In 1996, I was hired to liquidate the estate of a 'mad scientist' in San Diego. I found photographs of an ME 262 being reverse engineered at San Bernardino Air Materials Command (which later became Norton AFB). The photos were dated June, 1944. By then Norton AFB was shut down, and I couldn't find anyone who knew about it." 
The U.S. investigated the ME-262 to see how it stacked up against the Bell Aeracomet (first U.S. jet fighter, produced and flew in October of 1942) and the Hughes D-2 jet fighter (first flown on June 20, 1943 at Harper Dry Lake in the Mojave Desert).
The D-2's problem, however, was political. It used XF-11 (Spruce Goose) funds in order to keep it secret, and was so illegal that it "burned up" mere weeks after its successful proof of concept (a test in which it raced past some U.S. propellor-driven fighters in California).