h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Some years ago a series of articles was published in Street and Smiths
Astounding Science Fiction magazine(s) under a general heading of
"Deans Motion Device" this device was allegedly "patented" in the
U.S.A. It was also stated that it was available, to "the general
public" (no ban on access to the records) This information may be of some use to other researchers who are looking for "anti - gravity"
devices. If "Astounding Science Fiction" is still published by
Street and Smiths, back number copies may be available for perusal
and / or purchase.

The amazing and rather wierd inventer Nicholas Tesela was Russian, so any attept to keep his work hushed would probably be from the Russian Government and not the American.

Tesla was born a Croatian Serb and became a Naturalised American. All his papers were seized by the FBI when he died in New York in 1943. As he was born Croatian, he was born a citizen of a country the US was at war with (it was a Nazi client state). None of this means that Tesla was on to anything as regards anti-gravity. See http://www.bbc.co.uk/dna/h2g2/classic/A486182
for further details.