This is a very Wikipedia-centric viewpoint—in fact, English Wikipedia-centric. Wikimedia chapters operate around countries, not projects or even languages. (The United States has more Internet-connected Spanish speakers than probably any other country, and we could do a lot to help our still-struggling Spanish Wikipedia.)
There are already many WikiProjects and notice boards for American states and regions, but they don't take the place of a chapter (and neither will chapters replace them).
Austin