The inventor of the Big Mac has died at 98

The man who invented the quintessential American fast-food burger, the Big Mac, and inadvertently set off a race to create ever more expansive fast-food menus, has died.  

Michael "Jim" Delligatti passed away Monday surrounded by family at his home in a Pittsburgh suburb, according to his family. He was 98 years old. 

Delligatti laid claim to one of the most indelible inventions in American cuisine since sliced bread — a double hamburger with two beef patties, lettuce, cheese, pickles and onions, which is covered in a special sauce.

Read more: The sad story begind the world's cheapest Big Mac

As owner of a McDonald's restaurant in western Pennsylvania nearly half a century ago, Delligatti convinced the company to venture away from its brief menu of simple burgers, fries and drinks, according to a 1993 profile of the Big Mac in the Los Angeles Times.

He got permission to try his new burger in 1967 and sales jumped 12 percent, the Times said. Within a few years, McDonald's was advertising the Big Mac nationwide.

"This wasn't like discovering the light bulb," he said. "The bulb was already there. All I did was screw it in the socket."

He said the idea came from rival burger restaurants in the mid-1960s.

After the Big Mac's invention, the company expanded its menu further, creating an age of new menu items such as the Egg McMuffin and Filet-o-Fish.  

But, it was the Big Mac that became a cultural icon.  

In a statement, McDonald's said Delligatti was a "legendary franchisee" who made a "lasting impression" on the company.  

"We will remember Jim as an insightful franchisee, a knowledgeable businessman," the company said.  

McDonald's says it sells hundreds of millions of the oversized burgers globally, although sales have slowed in recent years as millennials reportedly show less interest in super-sized fast food.  

According to Delligatti's family he went on to own 48 McDonald's restaurants.

He is survived by his wife Ellie, two children, and a number of grandchildren and great-grandchildren.