I don't know about in the USA, but given the types of consumer access in use today, I wouldn't rely on it much beyond the country or perhaps state/province leve

I don't know about in the USA, but given the types of consumer access in use today, I wouldn't rely on it much beyond the country or perhaps state/province level. For consumer level ISP's, you're likely to just get the location of the ISP headquarters. If you need more accurate user location, I'd suggest looking into device location APIs - they aren't available all the time, and the user can reject/deny the request, but if accurate location is important and actually gives benefit to the user, that's likely a better solution.