How 7-Eleven's Slurpee Actually Started With Dairy Queen

Anyone who has had to make a late-night run to get milk, beer, or even just an evening snack has probably thanked their lucky stars that 7-Eleven exists. The convenience store is one of the largest franchise companies in the world, operating over 71,100 locations in 20 different countries, with the majority of them open 24 hours a day, according to 7-Eleven.

The very first 7-Eleven, which was the brainchild of Joe Thompson, opened up all the way back in 1927. Thompson had been working as an employee at Southland Ice Company in Dallas, Texas. Southland Ice Company sold, you guessed it, ice. But Thompson came up with a different way to use the company's product. He began selling a small number of necessities, such as milk, eggs, and bread, to customers during grocery stores' off hours, using the ice to keep the goods cold, according to Companies History. Customers loved the convenience of Thompson's little shop, and within just 10 years the late-night sundry store grew from a single retail ice dock to 60 locations. The new type of shop was affectionately called the Tote'm Store, so named due to the fact that customers would "tote" their own goods away.

In 1947, the company changed both its operating hours and its name 7-Eleven (as in, 7 a.m. to 11 p.m.), making the store even more convenient than ever. As the company grew, its offerings expanded well beyond basic necessities like milk and eggs, selling snacks, sandwiches, hot food, and of course, the famous frozen, sweet, slushy beverage known as the Slurpee. However, while Slurpees and 7-Eleven now go hand in hand, the convenience store's founder can't claim credit for its most famous drink. That honor goes to Omar Knedlik, a Kansas-based businessman and Dairy Queen franchise owner.

In the 1950s, after he returned from serving in World War II, Knedlik set to work owning and operating a Dairy Queen in Coffeyville, Kansas, according to Kansas Public Radio. However, maintaining the machines at his store was a struggle at times, leaving Knedlik one day faced with the problem of a malfunctioning soda machine. Of course, customers expected a cold drink, so Knedlik moved his sodas into the freezer, which was still operational. As one might expect, this caused the sodas to freeze slightly and develop a slushy-like texture. However, what Knedlik didn't expect was for his customers to come back requesting their sodas to be slightly frozen. Thus, the ICEE was born.

Knedlik's new ICEE sodas were a hit, so much so that he even invented his own homemade ICEE machine, using a car's air conditioning unit to freeze the beverage into the perfect slushy texture, according to Mental Floss. He got creative with the recipe, adding flavored syrup and carbon dioxide to make the perfect sweet, slushy drink, which he patented as the ICEE in 1960 (per Kansas Public Radio).

In 1965, the innovative Dairy Queen franchise owner struck up a licensing agreement with 7-Eleven, allowing them to purchase his ICEE machines and sell the beverage from their stores. However, the convenience store put its own spin on the product by changing its name to the Slurpee, inspired by the loud slurping sound one would make when trying to suck up the last of the sweet beverage through a straw. Just two years later, 7-Eleven had installed a Slurpee machine in every store operating in the United States, and before long, Slurpees would become one of 7-Eleven's most popular products. The drink became so famous that the chain even introduced National Slurpee Day in 2002, giving away free Slurpees to customers as a part of its 75th birthday celebration, according to National Today. Fans loved it so much that now, the famous franchise celebrates Slurpee Day every year on July 11, per 7-Eleven.