In the late 1960s, McDonald's franchisee Herb Peterson invented the Egg McMuffin in Southern California. It was introduced nationwide to customers in 1975.
An English muffin, one egg, melted American cheese and a piece of Canadian bacon make up the Egg McMuffin.
Denver McDonald's owner and operator Tom Carlson said breakfast is big business for the restaurant.
"Twenty to 30 percent of our business is done during breakfast," Carlson said.
Carlson runs the McDonald's at East Colfax Avenue and Pennsylvania Street in Denver.
9NEWS Business Reporter Gregg Moss asked Carlson how he gets the egg so perfectly round.
"They are fresh cracked eggs, and we crack them into a Teflon ring, and they come out hot and fresh," Carlson said.
McDonald's says it has 300 calories and recently added it to its new "Favorites Under 400 Calories Menu." That menu was announced during the 2012 Summer Olympics as a way to educate consumers about the calories in McDonald's favorite foods.
The first McDonald's was opened in 1955 by Ray Kroc in Des Plaines, Ill. with an original menu consisting of hamburgers, cheeseburgers, fries, soft drinks, milk, coffee and milkshakes.
For more on the history of the Egg McMuffin click on the attached video.
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