Well, there is a number of things to consider.
Language change: Unless we were re-colonized by another English-speaking country: say the United Kingdom or more creatively Australia-Canada-New-Zealand, Colonizing powers tend to spread their language on the lands that they colonize by making it the official administrative and educational language. Therefore you would see English largely sidelined in favor of the colonizer's language say French for example. The school would be taught largely in French and in order to get a job or at least be moderately successful, you would have to speak French fluently.
Citizenship and Rights: You would no longer be a citizen of the USA you would be considered either a subject or citizen of the colonial power therefore you would have to follow the laws of the colonial power. Unless we were re-colonized by a country that uses Common Law our system of Law would be reversed to that of the colonizer. In addition, in terms of rights, you might be sidelined people from the colonizer's country who would settle here would get top jobs and be largely treated more civilly, native dwellers would see themselves as second class citizens. However, there is always a flip to this historically the whites in "white colonies" in the British Empire such as Canada, Australia, New Zealand were seen as extensions of British people and thus treated well or at least equal.
Culture: Final change we would see if we were re-colonized would be another culture establishing dominance we would celebrate holidays of the colonizing power, our history lessons would be those of the colonizing power and their benevolence, and our common way of life would be shifted to adapt to the colonial power acting more like our colonizers or acting as a creole- mix where our culture would be one of native mixed with colonizer