USD is backed by literally nothing. LITERALLY NOTHING.
https://www.treasury.gov/resource-center/faqs/Currency/Pages...
> Federal Reserve notes are not redeemable in gold, silver or any other commodity, and receive no backing by anything
https://www.treasury.gov/resource-center/faqs/Currency/Pages...
> Federal Reserve notes are not redeemable in gold, silver or any other commodity, and receive no backing by anything
that is not quite right. historically USD has been backed by the USA military
funnily enough you CAN actually redeem the banknotes for these things but most people don't typically enjoy the experience