When I was younger (was born in '78), I remember seeing a special, stylized sign over many of the little 'mom 'n pop' corner stores in the area reading 'Unity-Frankford Stores.'

The one closest to where I grew up at in Olney was at Mascher and Spencer.

There are still a few of these signs around up here in the Northeast (and, perhaps around other areas of the city), but many of the stores are either vacant or have since become something different.

So, what exactly was a 'Unity-Frankford' store? It was some sort of chain, obviously, but, was each store individual owned?

Approximately how many were there, and around what years did these stores operate, etc.?