That was the case in Los Angeles. A black WWII veteran came back to LA after the war, dug a pit, and established Mr. Jim's BBQ, which became a small chain and served excellent food. However, the eateries didn't survive his death late last century. Greece's BBQ over on La Brea and the Pit south of Downtown LA were also good, as was Burrell's, a barbecue joint located in a residential neighborhood in Santa Ana. But they're all gone.
The only decent barbecue joint in LA that I know of today is Mom's, located on Imperial Highway in South-Central LA, but I think it's owned by Far-Easterners.
I started my BBQ journey at Big Sister’s BBQ on Lincoln Ave. in the heart of the hood. A ghetto BBQ sandwich is a slab of pork ribs laid on 3 pieces of white sandwich bread, a cup or two of BBQ sauce on the ribs and then 3 pieces of white bread on top. Wrap tightly in aluminum foil. BBQ sauce soaked white bread is the children’s dinner - the adults eat the meat.
I couldn’t get within 300 yards of that location today (now long gone from the riots) without getting jacked or jugged.