TAMPA, Fla. (WFLA) — Independence Day, known as America’s birthday, a day of fireworks, freedom, and celebration. The first was July 4, 1776. While hot dogs weren’t a national tradition during the Revolution, the popular July 4 food is now consumed by millions of Americans every year.

In fact, hot dogs didn’t kick off as an American tradition until almost 100 years later. So, how did the hot dog become a July 4 food?

According to NHDSC, it started in the 1860s. The origin of what became the American hot dog got its start in New York, where a report cited by the Hot Dog Council says a German immigrant sold a “dachsund sausage” on a milk roll with sauerkraut from a push cart. Then, in 1871, a hot dog stand opened on Coney Island, owned by Charles Feltman. NHDSC said Feltman’s stand sold “3,684 dachshund sausages in a milk roll during his first year in business.”

Then, 22 years later, the Colombian Exposition came to Chicago. The festival in 1893 “brought hordes of visitors who consumed large quantities of sausages sold by vendors,” with NHDSC saying the food was convenient and inexpensive, helping it pick up steam at the event.

The food spread to baseball parks in the same year, according to NHDSC, adding to its popularization.

Now, more than 150 years since Feltman’s Coney Island stand started selling its wares, Coney Island is home to a hot dog eating contest from Nathan’s Hot Dogs, with the contest itself running back as far as 1967.

According to the National Hot Dog and Sausage Council, Americans eat about seven billion hot dogs from Memorial Day to Labor Day. On July 4, the country eats 150 million hot dogs, day of. The organization said that’s enough hot dogs to connect Washington D.C. to Los Angeles more than five times, or more than 13,000 miles. The distance from Washington to LA is 2,668.3 miles.

Collectively, NHDSC said Americans spent $7.5 billion on hot dogs and sausages last year, just at supermarkets and grocery stores. The Nathan’s Hot Dog Eating Contest is traditionally held on July 4, though in some of its earlier years there were two competition days during the year.

July is also National Hot Dog Month, with NHDSC saying July 4 is the biggest day for hot dog consumption for the U.S.