Supermarkets as we know them today basically came into being during the 1950s. At the start of the decade supermarkets accounted for 35% of food retail dollars spent, and by the end of the decade that had doubled to 70%. The number of supermarkets in existence also doubled, from 14,00 in 1950 to 33,000 in 1960.
Consumers began doing all or most of their grocery shopping at one location, rather than visiting multiple specialty stores.
Supermarkets required relatively large lots, so were often on the outskirts of cities.
These large grocery stores features unusually large parking lots for the times to accommodate high numbers of customers, all or most of whom would arrive in a vehicle.
Customers started retrieving their own items from shelves with large selections, rather than an employee packing up requested items.
There was a much larger variety of the same types of products than grocery shoppers were accustomed to; grocery store chains carried up to 10,000 individual, nationally branded items.
Prices dropped significantly, as sales volume and average spend became the primary profit drivers over markup on individual products.
Locally grown produce began its decline at supermarkets in the 1950s, when stores started prioritizing lower prices from national suppliers. Large grocery chains were actually fairly devastating to local farmers. They also led to the demise of many a mom-and-pop specialized food store.
Plastic film and wrapping machines allowed for the introduction of prepared, pre-packaged fruits and vegetables at these stores, which had the funds, space, and manpower to use them.
Supermarkets made it easier for people to get all the ingredients for some of those horrifying foods of the mid-century years!