Looks like the VA portion of DC was returned to Virginia in the mid-1800's. Of course, I think that there is an legitimate argument to be had that if the Federal District were to be shrunk to just the main governmental areas, the rest of the city would automatically revert to Maryland's control, which would require their legislature to approve partitioning part of their state into a new state.
Oh, and 705,000 is totally the same thing as over 1 million.