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Happy Ice Cream Soda Day! It's unfortunate that we don't know who exactly invented the beloved sweet treat, because if we did, we could have one in his honor. Though Robert McCay Green is the guy who generally gets credit for the fizzy concoction, at least three others have claimed the idea was originally theirs. Here are their stories.

Robert McCay Green

Even though Green usually gets the recognition, there are still two versions of his story. In one, Green was a vendor at an exhibition in Philadelphia in 1874, serving sweet cream sodas to customers. His stand was so popular that he ran out of sweet cream and was unable to purchase more on short notice. He was able to find ice cream, however, and figured it would be a good substitute once it melted. But customers were anxiously awaiting their sodas, and Green decided that scoops of ice cream would have to do. By the end of the exhibition, he was doing $400 a day in ice cream sodas.

The other story, a first-hand account that’s likely more reliable, says that Green was simply trying to come up with a way to make his soda fountain stand out from others at the exhibition. He stumbled upon his ice cream soda idea while observing people enjoying ice cream with a glass of plain water at a local confectionery. Wondering why no one had ever thought to combine carbonated soda water with ice cream, Green came up with 16 soda combinations to serve with vanilla ice cream at the exhibition. After a shaky first day, word spread, and the ice cream soda became a hit.

Fred Sanders

Fred Sanders of Sanders Candy in Detroit also claimed that he invented the ice cream soda when his store ran out of sweet cream. He substituted ice cream, and voilà! The ice cream soda was born. Sanders didn’t open his store until 1875, however, so we have to give Green the edge on this one.

To be fair, the sweet cream/ice cream substitution makes perfect sense—so much sense, in fact, that seems entirely feasible that two different people could have thought of it independently.

Philip Mohr

Confectioner and baker Philip Mohr's ice cream soda story starts in Elizabeth, New Jersey, in 1862, when a local banker asked Mohr if he could somehow make his flavored soda water a little colder. Mohr sometimes mixed his own soda water with a little bit of ice cream and thought perhaps the concoction would fit the bill for his customer. He was right—the banker loved the drink and urged Mohr to consider opening a soda fountain in the financial district of New York. Mohr declined, but the banker spread the word to all of his high-powered financial friends, and ice cream sodas were soon in demand across the country.

George Guy

Finally, there’s George Guy. Guy worked for Robert Green at his Philadelphia fountain and was preparing two separate orders—a dish of ice cream and a glass of vanilla soda water. In his haste to get the orders finished, Guy accidentally dropped the ice cream into the soda water. He was getting ready to throw it out when the customer asked for a taste. It turned out to be delicious, and thus, the ice cream soda was born. Guy moved to Seattle in 1888 and set up his own soda fountain, where he liked to tell people the story of how he invented the delicious dessert.

If getting the last word counts for anything, Green definitely wins—his will specified that “Here lies the originator of the ice cream soda” be engraved on his tombstone.