Nearly 20 million people poured through the gates of the 1904 World’s Fair in St. Louis, which commemorated the centennial of the Louisiana Purchase. While hungry ticket holders could order off a global menu at more than 125 eateries, a distinctly American cuisine emerged at the Louisiana Purchase Exposition. Hand-held items—and fast-food precursors—proved popular with busy fairgoers who ate on the go.

The 1904 World’s Fair “changed how the Western world ate and snacked,” food historian Elizabeth Abbot writes in Sugar: A Bittersweet History. Many visitors to St. Louis had their first tastes of foods and beverages that would become American staples such as hot dogs, hamburgers, iced tea and the following fare:

The fair’s Palace of Electricity housed not only the world-changing innovations of Thomas Edison but an invention that harnessed cutting-edge technology to create a sweet concoction: cotton candy. Visitors watched with curiosity as the Electric Candy Machine Company’s device created sticky strands of candy by forcing liquefied sugar through small holes in a heated bowl spinning 2,200 times a minute. The machine had been co-patented by candy maker John C. Wharton and an unlikely collaborator, dentist William Morrison.

Although many hesitated to sample the company’s “fairy floss” until they were reassured it was truly candy and not cotton, the fluffy treat became one of the fair’s biggest hits. In addition to a prize for “novelty of invention,” the Electric Candy Machine Company sold tens of thousands of cotton candy boxes that were decorated with colorful lithographs of the fairgrounds and designed to be mailed to friends and family as souvenirs.

The boxes broadened the cloud-like confection’s popularity well beyond the fairgrounds. After the exhibition, the Electric Candy Machine Company capitalized on the publicity by installing machines in drug store windows around the country, and cotton candy quickly became a perennial fairground staple.

Some food historians credit cereal pioneer John Harvey Kellogg with developing modern peanut butter at his Battle Creek Sanitarium. Others assert that St. Louis snack food maker George Bayle was the first to manufacture and sell the product in 1894.

A decade later, Missouri farmer C.H. Sumner arrived in Bayle’s hometown to exhibit his nut butter varieties and recipes at the World’s Fair. Sumner touted nut butters as protein-rich food sources for those unable to chew meat or concerned about the safety of American meat products. “Whether considered from the standpoint of nutrition, economy or hygiene, it is quite evident that nuts are superior to meats for food,” he wrote in the Western Fruit-Grower.

Using a pioneering grinding machine, Sumner was peanut butter’s lone concessionaire at the exhibition. Fairgoers collectively spent just over $700 at Sumner’s stand, and the treat’s popularity soon spread as Beech-Nut launched the first nationwide brand of peanut butter later that year. American peanut butter production exploded from 2 million pounds in 1899 to 34 million pounds in 1907.

Prior to the fair, vendors sold ice cream in glass cups or dishes called “penny licks” that were returned, rinsed and reused. During the exhibition, however, the St. Louis Globe-Democrat noted a novel sight—fairgoers were eating ice cream out of “an inverted cone of hard cake, resembling a coiled-up waffle.”

Proving the adage that “success has many fathers,” several people claimed to have invented the ice cream cone at the 1904 World’s Fair, including Ernest Hamwi. As a 16-year-old recent immigrant from Syria, he sold zalabias—waffle-like pastries from the Middle East—at the “Constantinople on the Pike” exhibit. According to Hamwi, when a neighboring ice cream concession ran out of dishes, he rolled a zalabia into a funnel shape for use as an edible container.

“This idea seemed to go over big,” he told a St. Louis newspaper decades later, “and soon the ice cream concessions all over the fair purchased the rolled waffles from us and sold them with the cream and called them ‘cornucopias.’” After the fair, Hamwi worked as a traveling salesman for the Cornucopia Waffle Oven Company before starting his own ice cream cone company in 1910.

Although the ice cream cone may not have been born in St. Louis—an Italian immigrant in New York City, Italo Marchiony, patented a mold to make 10 ice cream cones at a time in 1903 and claimed to have served them since 1896—the World’s Fair quickly made it a popular novelty at seaside resorts, county fairs and amusement parks. “Being new and toothsome, it is said to be the best money-maker for fairs and public gatherings yet devised,” the Roanoke Evening News reported in 1905. Given its historical connection to the fair, the ice cream cone became Missouri’s official state dessert.

Dr. Alexander Anderson made quite a bang at the World’s Fair. Visitors waited 30 minutes or more to watch Anderson’s thundering cannons blast blizzards of puffed rice inside the Palace of Agriculture.

The botanist had discovered that when he smashed airtight, super-heated glass tubes filled with powdered starch, the sudden pressure drop caused the starch to puff to eight times its size as the water inside vaporized and expanded. Anderson received a patent in 1902 for his invention, and the American Cereal Company, maker of Quaker Oats, acquired it to produce puffed rice and puffed wheat breakfast cereals.

The puffed grains proved a hit at the World’s Fair as visitors thronged the American Cereal exhibit to see—and hear—Anderson’s puffing machine in action. Fairgoers bought more than 20,000 pounds of caramelized puffed rice in St. Louis, and many sent home samples of the tasty treat later branded as “The Food Shot from Guns.” Anderson’s invention, which the Michigan Tradesman dubbed “The Eighth Wonder of the World,” revolutionized breakfast and led to the production of popular cereals such as Rice Krispies, Kix and Cheerios, along with snack foods such as Cheetos.

Peter Cooper, developer of the steam locomotive and founder of Manhattan’s Cooper Union college, obtained the first patent for manufacturing powdered gelatin from animal by-products in 1845. But he made little inroads in selling gelatin as a dessert. Pearle Wait, an upstate New York cough syrup manufacturer, bought the gelatin patent from Cooper’s estate in 1897 and added fruit flavors to the dessert that his wife, May, named “Jell-O.” When door-to-door sales lagged, Wait sold the Jell-O business for $450 to fellow townsman Orator Frank Woodward, owner of the Genesee Pure Food Company.

Woodward launched an aggressive marketing campaign that included an exhibition inside the Palace of Agriculture at the 1904 World’s Fair demonstrating how to make Jell-O by adding hot water to the gelatin powder and then setting it to cool. After watching it wiggle and seeing it jiggle, curious fairgoers tasted Jell-O samples, which came in six flavors including chocolate, and took home recipe booklets. (Jell-O also exhibited its ice cream powder, which could be dissolved in milk and frozen.) Jell-O advertisements trumpeted the gold medal that the “delightful and quick dessert” won at the fair, and the exhibition helped Jell-O sales to quadruple between 1902 and 1906, when they topped $1 million.