Was the cheeseburger invented in Louisville? This restaurant claims it was.

A bronze plaque inside a Louisville restaurant makes a whopper of a claim: "Kaelin's — Birthplace of the Cheeseburger." Given the cheeseburger has been a beloved American fast-food staple for decades, that's a pretty bold statement, but is it true?

Here's what we know.

Was the American cheeseburger invented in Louisville?

Monday marks the 90th year that restaurant-owner Carl Kaelin slapped cheese on a hamburger shortly after opening for business in 1934. The tale of how the cheeseburger came to be in Louisville is from the granddaughter of the original owners.

"Initially we were a neighborhood bar, but during the day we sold lunch to the kids across the street,” said Irma Kaelin Raque in a 2017 phone interview with the Courier Journal.

Raque, then 85, said she helped run Kaelin's Restaurant on Newburg Road until it closed in 2009 and could remember helping her mother take hamburger orders when she was a 3-year-old. She described her mother cooking burgers one day when her father casually suggested putting cheese on them.

Three burgers later, he couldn’t get enough, Raque explained.

“It became popular and grew by word of mouth. We stayed with it for 75 years,” she said.

'Dibs': Other states claim cheeseburger's invention

Despite Louisville's claim to fast-food fame, other states have gotten salty over the cheeseburger's invention.

"The Rite Spot" was a roadside burger stand near Route 66 in Pasadena, California, and the place where the cheeseburger was first served to customers, according to the Pasadena Convention and Visitor Bureau.

Legend has it the owner's 16-year-old son, Lionel Sternberger, was flipping patties in 1924 when he accidentally burnt one. To hide his mistake, Sternberger orchestrated a "cheesy cover up," officials said, by tossing a slice of cheese onto the burger to mask any scorch marks. The rest is history.

...Unless you live in Colorado.

In 1935, the trademark for the name "cheeseburger" was awarded to Louis Ballast of the Humpty Dumpty Drive-In in Denver. A 1987 marker commemorated Ballast as the cheeseburger's creator, according to Denver.org, which writes that Ballast first experimented with burgers topped with chocolate and peanut butter (seriously?), but taste testers preferred cheese instead.

Kaelin's Restaurant in Louisville has one more fast food surprise: ties to KFC

Kaelin's Restaurant helped change America's fast-food landscape whether it invented the cheeseburger or not.

Raque remembers opening presents one Christmas morning when a knock came at the back door. It was Harland Sanders (yes, that Harland Sanders, who would go on to found KFC). He and Kaelin were friends before the colonel launched his 11-spice recipe that became internationally famous.

"Mother answered and she said, 'Pappy Sanders, what are you doing here? It's Christmas'," Raque told the Courier Journal.

"He said, 'I've got a deal to make you rich.'"

The Kaelins began selling Sanders' chicken at its original location along with a second restaurant on Dixie Highway, appropriately named Kaelin's Kentucky Fried Chicken. But when it came to investing in the company, Carl Kaelin notoriously turned his friend down.

"Granddad couldn't see putting 10,000 bucks into it," Tommy Raque told the Chicago Tribune in 1992. "If he only had, I might not be standing here, frying cheeseburgers."

John Tufts covers trending news for the Indianapolis Star. Send him a news tip at JTufts@Gannett.com. Chie Davis contributed to this article.

This article originally appeared on Indianapolis Star: Louisville restaurant claims it invented the cheeseburger.