The wikipedia page that lists which US grocery chains are grouped under the same operators
I have been wanting a database site that groups US grocery store chains and displays them geographically for a while. As far as I can tell, such a site does not yet exist. This makes it much harder for me to be sure about the things I say in those conversations everyone in the US has a couple times a year about well where I come from the main chain was THIS or well did you know the crazy thing MY local chain used to do, etc etc.
There is however a wikipedia page which shows which chains are operated by the same parent company. You can find it here. I found it pretty interesting - in particular, the "Notable local chains" and "Ethnic chains" sections. The "ethnic chains" section does seem to include some chains like H-Mart that are so common that I would have put them up in one of the larger sections at the top of the page.
The page lists to a list of defunct stores which I also found pretty interesting.
All these lists are a bit vague and overlapping. I found one on the "defunct" list, Haggen, which just says "acquired by Albertsons. Several locations still exist." So it's not defunct, right? Fresh Thyme Market also appears in multiple lists. I suppose my dream of the Master Map of All Regional Supermarkets is a bit of a pipe dream... maintaining it as this industry expands and contracts would be a total pain. And the question of what a brand means - whether it still counts when it's just a mask that Albertsons is wearing - is a kind of library-science-ass question I'm not totally prepared to answer.