McDonald’s is one of the world’s biggest and most influential restaurant chains, proudly proclaiming on its iconic "Golden Arches" signs to have served "billions and billions" of meals. They’re successful for a reason, efficiently and consistently cranking out tasty, easy, and comforting food, and a great many of its menu items could make a claim at being its "signature" offering, be it the Big Mac, Quarter Pounder with Cheese, Chicken McNuggets, Egg McMuffin, or those near-universally acclaimed fries.

But no matter what gets ordered from the McDonald’s counter or drive-thru window, it needs something to help wash it down, and for millions of customers every day, that’s a soft drink. For decades, McDonald’s has dispensed Coca-Cola products, like Coke, Diet Coke, Sprite, and more. The drinks are cold, sweet, refreshing, and plentiful, earning the McDonald’s soda line as many fans as the food has. It’s taken a lot of time and effort for McDonald’s to lock down its soft drinks — here’s a long sip into the history and mechanics of soda at McDonald’s.