It would be unusual for a US receptacle to have an internal fuse or circuit breaker, although if it was a GFCI outlet (the kind with the "test" and "reset" buttons that you see in kitchens and bathrooms), it could've detected a ground fault and shut off. (It's also possible for several regular outlets to be wired to a single GFCI outlet, so check any nearby GFCI outlets to see if they've been tripped.)
It sounds like you went to your circuit breaker panel and checked that none of the circuits are tripped, but you may want to double-check that. Even if a device is on constantly doesn't mean its electrical draw is constant. E.g. fridges and air conditioners are highly variable in their power consumption from minute-to-minute. (For that matter, anything with a motor like a fridge can nuisance-trip a GFCI outlet...)
I suppose it is possible that you had excessive current burn out an old outlet or a bad connection. You could take the cover off the outlet to look for any signs of smoke or burning that might accompany such a failure.
If you see no signs of electrical damage and can't find any circuit breakers or GFCI outlets that are tripped, I would say you should replace the outlet.
