In 1917 the U.S. government granted a patent for a grocery store.
Not a machine in a grocery store. The store.
Patent number 1,242,872. And when you read the actual document, which almost nobody does, you find something much stranger than a nice idea about shopping.
It describes a one-way maze.
The customer enters through a gate that locks behind them. They pick up a basket. Then they walk a fixed path that, in the inventor's own words, “must be traversed by every purchaser who enters the sales room.”
At the end there is another one-way gate. You cannot leave without passing the register.
And above the shelves, there are walkways. For a supervisor to stand on and watch you.
That is Piggly Wiggly. That is the origin of every grocery store you have ever been in.