No, children, the roads, streets, and highways were not always infested by fast-food chains, or even chain restaurants for that matter.
The first Mexican fast food place Brian remembers eating in was a little place in Barstow California called Taco Tia.
He stopped there once as a kid in the late 50s driving to or from Las Vegas with his parents. It looked exactly like this.
It probably wasn't much, but what an exciting break it was from a drive across the Mohave desert in a car without air conditioning (only really rich people had air-conditioned cars back then). Fast food walk-up-to-the-window joints were a revolutionary concept back in those days, although drive-ins had been popular for some time.
The person who started up Taco Tia was Glen Bell. A few years later he went on to found Taco Bell. Now we know why there's that Bell in the name. No wonder that 1958 Barstow taco tasted special.
Brian can also recall Fosters Freeze from 1950s California, which makes sense, since they claim to have been The Golden State's first fast-food chain.
You'll find a handy list of restaurant chains that started in the 1950s here. Even that list is incomplete, since it doesn't include Chicken Delight, also founded in 1952. What a troubled legal history that place had. Their rhyming-couplet singing commercial, "Don't cook tonight - call Chicken Delight!" , was famous in its day. Unfortunately, the melody in that 80s version differs from the original still running through Brian's head.
Ah... singing commercials. They don't make 'em like that anymore either. Doesn't this just make you want to run out to buy some Ajax? We'll save those reminiscences for another day.