On this day in 1916, Clarence Saunders opened Piggly Wiggly in Memphis, and for the first time a person could walk into a grocery, pick up a basket, and go get the flour themselves.

Think about what that replaced. You came in with a list, or with a sentence you'd rehearsed on the walk over, and you handed it across a counter. A clerk went behind and fetched things, weighed out what you asked for, and you stood there waiting with your hands empty, taking whatever price he said. Piggly Wiggly put a price on every single item, in the aisle, where your own eyes could get at it. Checkout stands at the front. Turnstiles, shelves, the whole route laid out so you walked past everything on your way to the eggs.

Which is the part I love and the part that ruins me. Nobody wandering a shop has ever left with only what was written down. I have gone in for yeast and come out with three tins of something because they were at eye level and the label was pretty, and the yeast, of course, still sitting on the shelf in Memphis. That morning in 1916 is the morning shopping for dinner turned into a walk rather than a wait. The Wikipedia article is linked below if you want the rest of it.