Free Slurpees At 7-Eleven: Chain Celebrates 85th Birthday With Massive Giveaway

Happy birthday, 7-Eleven! The convenience store chain celebrates its 85th birthday on July 11 with free 7.11-oz. Slurpees at participating locations from 11 a.m. to 7 p.m.

Here's 7-Eleven's store locator. Call the location nearest you to find out if it's running the deal.

The event also marks the 45th birthday of 7-Eleven's iconic frozen drink, the Slurpee. The chain plans to dole out seven million free ones this year, which would exceed last year's figure of two million to become the most Slurpees given away in the company's history.

7-Eleven's story can be traced back to 1927, when Southland Ice Company employee Joe C. Thompson started selling milk, eggs and bread out of an ice house. Thompson became so successful that he bought the entire company, keeping his stores open from 7 a.m. to 11 p.m. By 1952, he'd opened 100 stores under the 7-Eleven brand. As of 1991, the company has been run by Japanese group Seven & I Holdings Co. with more than 46,000 stores in 16 countries.

In a release, 7-Eleven explains how a mishap at a drive-in hamburger eatery sparked the genesis of what became known as the Slurpee:

When the soda fountain broke at his drive-in hamburger restaurant, proprietor Omar Knedlik began serving his customers icy-cold bottled soft drinks that he kept chilled in a deep freeze. Customers clamored for the slushy semi-frozen bottled drinks, and Knedlik hit upon the idea of creating soft-serve frozen drinks.

Knedlik later approached the John E. Mitchell Company with the idea, which resulted in the creation of a machine that used compact freon refrigeration to freeze a carbonated drink and serve it in a sherbet-like form. Dubbed the "Icee machine," in 1965 it was noticed by a visiting 7-Eleven manager who bought three of them. By 1967, they were in almost every 7-Eleven store.

Click through the below gallery from some retro images of 7-Eleven's past, from horse-drawn ice trucks to the high-tech machinery of modern day.