Which McDonald's breakfast sandwich did Herb Peterson create?

Herb Peterson created the Egg McMuffin for McDonald's.

Peterson owned a McDonald's franchise in Santa Barbara, California, and developed the sandwich in the early 1970s. It placed a freshly cooked egg, Canadian bacon, and cheese between the halves of a toasted English muffin. The format gave McDonald's a portable breakfast item with a distinctive identity.

The sandwich was first tested in 1971 and added to McDonald's national U.S. menu in 1972. Its success helped establish breakfast as a regular part of the chain's business and encouraged the expansion of a broader morning menu.

The Egg McMuffin is often mixed up with later breakfast products such as the McGriddle. The McGriddle uses griddle cakes with embedded syrup flavor, while the Egg McMuffin retains Peterson's original English-muffin format.