U.S. universities on-campus residence for International PhD students?
If you do the following search on Google, you will find some universities that do: "married student housing for graduate students". But I doubt that most do and the ones that provide this service would be large universities. Housing isn't free, of course, but it can be priced fairly low. It is possible that it is market priced in some places and provided only for convenience, but I think that it is most likely subsidized by the university nearly everywhere it is offered. 

I took advantage of this long ago so my experience is likely no longer valid, but the search will get you started. In my case it was very very low and included all utilities.