Tuesday is the day late-sleeping Egg McMuffin fans have been waiting for: starting Oct. 6, McDonald’s will begin serving breakfast all day, across the United States. It’s a move that’s been decades in the making for the fast-food chain, which introduced the popular sandwich in the mid-1970s.
Like Silly Putty and Penicillin, the Egg McMuffin has an origin story that only adds to its mystique: in this case, it’s the tale of how a McDonald’s franchise owner had to pretty much trick McDonald’s owner Ray Kroc into trying the first one, knowing that Kroc might have otherwise dismissed the idea.
Kroc told the tale in his 1977 autobiography, Grinding it Out: The Making of McDonald’s, shortly after the sandwich was introduced. It started on a fateful 1972 trip to Southern California. Herb Peterson, who ran a McDonald’s in Santa Barbara, asked Kroc to come take a look at something. But no matter how much Kroc asked, Peterson wouldn’t say what it was. The rest was history:
Meanwhile Patty Turner, the wife of a McDonald’s executive, came up with the name that Kroc credited with putting the new menu item over the top: Egg McMuffin. Though Kroc would note that it took three years to get the Egg McMuffin completely integrated into the McDonald’s system, by late 1973 TIME was already praising the sandwich—which went for 63¢ at the time—as an example of how the chain “pays close attention to suggestions from behind the counter.”
With the Egg McMuffin came the opening up of the entire fast food breakfast market. “It was exhilarating to see the combined forces of our research and development people, our marketing and advertising experts, and our operations and supply specialists all concentrating on creating a program for catering to the breakfast trade,” Kroc wrote in his book, five years after the Egg McMuffin’s introduction. At the time, McDonald’s was still figuring out how to deal with some breakfast snags—such as how to serve pancakes when pre-cooked flapjacks are particularly gross—and convincing store operators to work longer hours. “Consequently, the breakfast program is growing at a very moderate rate,” Kroc added. “But I can see it catching on across the country…”
By 1981, breakfast accounted for a full 18% of McDonald’s sales, TIME reported. Within the next few years many competitors had introduced their own breakfast offerings, realizing that the morning rush was a natural fit with fast food. Eating breakfast from Jack-in-the-Box meant an extra half-hour that was “well spent sleeping,” a San Francisco security guard told TIME.
Now, more than 40 years after Ray Kroc’s trip to Santa Barbara, the night shift can benefit from that logic too.
Read TIME’s 1973 cover story about McDonald’s, here in the TIME Vault: The Burger That Conquered the Country