The Egg McMuffin was McDonald’s first breakfast sandwich served nationwide in the United States.
Herb Peterson created the sandwich in 1971 in Santa Barbara, California. It used an English muffin, a round egg, Canadian bacon, and cheese, giving McDonald’s a portable breakfast product with a distinctive visual and ingredient identity.
McDonald’s tested breakfast service in selected restaurants before expanding it across the United States. The Egg McMuffin became the signature item of that expansion and helped establish breakfast as a major part of the chain’s brand.
The sandwich is often described as the first McDonald’s breakfast item, but that wording is broader than the precise historical claim. Other breakfast foods and limited tests existed; the Egg McMuffin is the nationally recognized breakfast sandwich that anchored the menu’s expansion.