The Federal government NEVER had the constitutional right to own more property than enough to put a building and a parking lot on. It did not own land in the 13 state that created it but had to beg for a place, not exceeding 10 miles square, to put its capital. But it extorted all the new states by claiming almost all of their land as property in return for the grant of state sovereignty. And then over the years it took most of that back.