Why is Arlington County not a city?

[I spent the winter writing songs about getting better]

Virginia has some law that prevents incorporation once a county is above a certain population density. Yes it makes absolutely no sense.

[I spent the winter writing songs about getting better]

I’m looking at the some of the independent cities which are county-sized—Chesapeake and Virginia Beach—and they reached present form when small independent cities within the county’s historical boundaries annexed the remainder of the county. So I think the operative question is why Alexandria declined to annex it when it had the chance.

Alexandria intentionally split from it and then incorporated as a city so that'd be odd if it did.