Does US have standards for smart power outlets?
Usually you'll want to be certified to be compliant with appropriate UL standards (and FCC) in order to sell in the US. Testing can be done by various labs, not just UL, for example CSA and ETL. Since your device is an "intentional radiator" of RF the FCC compliance may be a bit more involved than if it was a simple MCU-based device. 

The standards (as with European standards) are not free, but sometimes you can find them at a library.