NEW YORK – If it’s fast and convenient, chances are you can find it at a convenience store. For more than 50 years, 7-Eleven has been serving customers its iconic Slurpee, and for more than 100 years Americans have been eating a product ubiquitous with convenience store food fare: the hot dog.

In honor of the 100th anniversary of the Nathan's Famous Hot Dog Eating Contest, TIME magazine is taking a look at how the name “hot dog” came to be here in the United States. Nathan’s founder, Polish immigrant Nathan Handwerker, may be one of the most famous hot dog makers in history, notes TIME, but the term “hot dog” had been in use well before he started his business.

Although the inventor of the term “hot dog” is debatable, references to hot dog carts as sporting events appeared in newspapers during the 1880s and 1890s. TIME writes that the “hot” part of the name may be due to the sausages being referred to as “red hots,” while the dog part may come from what the sausage is made up of, according to Bruce Kraig, historian and author of “Hot Dog: A Global History," and "Man Bites Dog: Hot Dog Culture in America.”

“The origin is that it’s a joke about what went into the meat itself and the running joke that once a butcher set up shop, all cats and dogs in the neighborhood disappeared,” Kraig told TIME. “Somebody—we’re not sure who—coined the term ‘hot dog’ because there were lots of cartoons from this period about dogs going into sausage machines, and that song ‘Oh Where, Oh Where Has My Little Dog Gone?’ But you’ll see ‘red hot’ and ‘hot dog’ kind of merge together in this period.”

TIME writes that the first food-cart vendors put the sausages in buns so they could be eaten without utensils by factory workers, and at the turn of the 20th century, when going to the beach became more widespread, hot dog carts became a popular food option at places like Coney Island.

“Americans have always eaten fast, always on the run,” Kraig told TIME. “Already in a casing, already cooked, the hot dog is the first really-fast food.”

7-Eleven, which got its start in the 1920s as the Southland Ice Company, helped popularize the grab-and-go, roller grill hot dog in the 1970s. In fact, the chain sells a Big Bite hot dog every 2.7 seconds of the day. And earlier this year fast-food chain Burger King sought to become the biggest seller of hot dogs in the United States by adding them to its menu.

The celebration of hot dogs continues on July 23, designated as National Hot Dog Day.