I would be very surprised if there aren't such resources provided by the U.S. Government somewhere. Let's have a look.... First hiccup here is that I'm not a U.S. citizen, so I'm not that familiar with the machinery of the thing. Is there a Department of Commerce? Check Google - yup, and it even has a sensible URL that I should have been able to guess myself.
Huh, it's running a bit slow; tell you what, the Census Bureau's listed here, let's have a look at that.
Hmmm.... there's a link on the front page of that to quickfacts.census.gov. Pick a state and it comes back with a bit of guff about it - oo, and it offers to drill down by city. Obviously, stuff gathered from census results. Is that the sort of "content" you're after? Hm. One of the links on the dataset collection is to something called "fedstats.gov". More stuff there, I guess. Meanwhile, back at census.gov, there's a link to "data tools" including mapping and direct file listings.
Ain't the Net a wonderful resource?