The Egg McMuffin, introduced in 1971, became McDonald’s first nationally successful breakfast sandwich brand.
Herb Peterson, a McDonald’s franchise owner in California, developed the sandwich with an English muffin, a round egg, Canadian bacon, and cheese. Its design made breakfast portable and helped McDonald’s build a permanent identity around morning service rather than treating breakfast as a minor side offering.
The Egg McMuffin is often confused with the Sausage McMuffin, which uses sausage instead of Canadian bacon, or with later products such as McGriddles. Those items expanded the breakfast menu, but the Egg McMuffin was the foundational branded sandwich.
Its name also illustrates McDonald’s product-branding style. The “Mc” prefix linked a specific menu item to the parent brand while leaving the distinctive “Muffin” name to describe its format. This combination made the product easy to remember and easy to identify in advertising.