Vintage photos show what it was like to eat at McDonald's in the 1970s

Product shot of a McDonald's Big Mac hamburger in 1977.

Henry Groskinsky/The LIFE Images Collection/Getty Images The first McDonald's franchise opened in Des Plaines, Illinois, on April 15, 1955.

By the 1970s, McDonald's had grown into a popular fast-food establishment.

The Quarter Pounder, Quarter Pounder with cheese, and Egg McMuffin were also added to the menu.

By the 1970s, just a decade into its operation under businessman Ray Kroc, McDonald's was already a thriving company that had served millions of customers.

The McDonald brothers had opened their small burger and barbecue joint in 1940, and when Kroc visited them in 1954, he saw promise in their ability to serve customers quickly by keeping burgers warm under a heat lamp.

Kroc opened the first McDonald's franchise location in Des Plaines, Illinois, on April 15, 1955.

That year, he also founded McDonald's System, Inc., which would become the McDonald's Corporation we know today.

By 1958, McDonald's had sold 100 million burgers, and the restaurants had adopted a signature design style prominently featuring the chain's iconic "golden arches." In 1961, Kroc bought the McDonald brothers out, and by the 1970s, the company was going from strength to strength, introducing drive-thrus, breakfast options, and the PlayPlace.

Here's what it was like to eat at McDonald's in the 1970s.

Before the introduction of high-tech cash registers, McDonald's employees took orders by hand and gave them to the kitchen.

Workers at a McDonald's take orders from customers in 1973.

Stephanie Maze/San Francisco Chronicle/Getty Images By the 1970s, the company was well-established and beginning its global expansion.

In 1967, the first McDonald's restaurant outside the US opened in Richmond, British Columbia.