Make Guam a county of Hawai’i. Make American Samoa another county of Hawai’i. Etc.
I call dibs! 
There’s currently a proposition looking for signatures to divide California into five states. Yeah, that’s sure to get approval in Congress.
I don’t think there will be any new States for generations and generations. About the only way I’d see it happening maybe is if some of the larger States just become unwieldy or it becomes so ridiculous that they only have two Senators that there is a broad movement to split them up into multiple states.
But there’s probably a more likely chance the Senate is reformed in some way before that happens (or better yet, rendered mostly irrelevant like the British House of Lords or the Canadian Senate.)
Realistically I think there are good arguments to be made about splitting up various States based on population size and/or disparate geographic/political reasons. Other than just never bothering to think about it rationally there’s really no reason California should be one State, or Texas either, although due to how we accepted Texas it would’ve been more difficult politically to have split it up at first.
FWIW I believe Constitutionally as long as the State itself agrees there is no problem with legally splitting a State up. The legal fiction under which Virginia was cut in two was that the legislature approved it (an illegal legislature based out of Wheeling that represented maybe 1/3rd of the territory that was actually given to West Virginia, primarily the Northern counties around Wheeling itself.)
I actually think the two most eastern counties in West Virginia absolutely should be given back to Virginia, at the very least.
I think what’s more likely to happen is re-drawing of current state lines. North & South California may split; those counties in northern Colorado that voted to secede may join Kansas; southeast Wisconsin, northeast Illinois, and northwest Indiana may create a new state; etc.
In practical terms, the City of Washington no longer exists. There is no governmental agency or official whose title or name includes a reference to the City of Washington. Every office or official act is taken in the name of the District of Columbia.
No longer exists as a legal jurisdiction, I should say. Obviously it exists as a concept, because people do refer to “Washington” in various contexts – although locals almost always call it “the District” or “D.C.”
Vietnam.
No wait, I know.
Scotland.
As I’ve said before, I don’t understand why Midway hasn’t been annexed into Hawaii already. It’s part of the Hawaiian Islands chain, and these days it’s just a nature reserve of no great value anyway.
How come there’s no option for Texas (by readmission to the union post-secession)? 
South Vietnam.
Why?
To convince you to start following sub-threads of discussion more closely, apparently.