When we were kids, fish was not that commonly served in midwestern households. Our parents' palates were not that adventurous and we kids thought fish smelled funny, except for fish sticks and Filet O' Fishes at McDonald's, and the occasional fish Dad would fry up from his trip up North with his buddies.
But we do remember going to a chain called Arthur Treacher's Fish and Chips. We knew it was British-tinged, but we didn't know its namesake was a Brit actor famed for playing a butler. (He was also Constable Jones in "Mary Poppins" -- now that, we saw!)
Bluntly, we didn't mind Arthur Treacher's fish because it wasn't fishy. It was the first place we had ever seen malt vinegar, which soaked the fries and after a while, seemed like an acceptable condiment. I seem to remember the wallpaper was fake British newspapers, perhaps referencing the famed newspaper-wrapped fish and chips of jolly old England. They also had a green-and-yellow lantern sign in front of each location. Some signs now have been repurposed to hawk whatever business replaced them.
According to Wikipedia, the chain served Icelandic codfish until it was sold in 1979 to Mrs. Paul's, of frozen fish stick fame, who "immediately replaced the Icelandic codfish with less expensive pollock."
Dunno if that had anything to do with it, but it was about that time that Arthur Treacher's started to vanish, at least from our area. The one we went to became a Winchell's Donuts, I think. Apparently there are 45 left in 8 northern states. They seem to be connected with a chicken place I never heard of -- Pudgie's. (Is naming your chain after a nickname for "chubby" ever a good idea? We're looking at you, BLIMPIES?)
Do you remember this chain? There are a few other fish chains out there -- Long John Silver's, H. Salt -- were they a part of your childhood? (Note that in the oh-so-Seventies 1979 commercial below, they actively try and downplay the fish.)