MCDONALD’S first ever restaurant opened its doors 77 years ago Monday — and now the fast food giant serves around 68 million customers every day.

McDonald brothers Dick and Mac proudly opened up the fast food outlet in 1940 in San Bernardino, California, where they flogged hamburgers for just 15 cents, The Sun reports.

Before the Golden Arches became world-renowned, the original menu was extremely simple.

For food, hungry punters could get their hands on hamburgers, cheeseburgers and French fries.

The drinks options were equally simple, as the first McDonald’s store offered up choices of coffee, milk, coke, root beer, orange or malt shakes.

By limiting the number of choices available, the kitchen could get orders out to customers more quickly. The McDonald’s assembly line was soon dubbed the Speedee Service System, which paved the way for modern day fast food culture.

Three years after opening their first store, the menu was expanded slightly. Ice cream sodas, sundaes and frosted root beer were among the drinks to be rolled out.

Some of the unusual menu items included the posh-sounding “Aristocratic Hamburgers” and “Peanut Butter and Jelly with French Fries”.

Two Mexican-inspired dishes were also being offered up — straight Chilli and Tamales and Chilli with French Fries. Barbecued treats also soon became a fast food favourite, with the 1943 menu boasting: “We barbecue all meats in our own barbecue pit”.

The future of McDonald’s changed forever when business mogul Ray Kroc visited the highly popular diner in 1955. As Kroc was so struck by the speedy service and simple food menu, he made plans to turn the outlet into an entire chain.

The shrewd businessman promised to give the McDonald brothers a one per cent cut of all earnings, but they were soon ditched from his plans. After shaking hands with his business partners, he went back on his word and the pair was forced to take their name off the original restaurant.

Over the decades, McDonald’s has introduced and axed dozens of different menu items to keep up with demand. Even though the original menu is humble in comparison to the extensive range of choice available today, the McDonald’s burger has endured the test of time throughout it all.

The Fiscal Times have estimated that the fast food chain sells more than 75 hamburgers every second. And the menu is continuing to expand.

The fast food giant recently trialled curly fries in some of their Asian outlets, but the delicious side dish is yet to be rolled out globally. And McDonald’s is now serving McFlurry ice-cream in giant buckets in France and Spain.

This article originally appeared on The Sun and was reproduced with permission.