Sonic's 1950s Menu Items Had Familiar Classics, Including 'The Whopper' — But Not The One You Think

America's long and loving relationship with fast food has given the world some truly iconic items that really don't need an introduction. The name Big Mac is immediately associated with McDonald's, just as the Frosty is firmly linked to Wendy's, and a Double Double can only be from In-N-Out. Which is why, while Sonic's 1950s menu features several familiar classics, one item doesn't quite seem to fit. For most people, The Whopper has long been associated with Burger King's stacked, juicy beef burger. But Sonic's version was something entirely different, as it contained no beef at all. Instead, it was a simple four-ingredient fish sandwich.

Fast food history fans have shared images of a 1959 Sonic Drive-In menu on various social mediaplatforms. The menu includes a few items Sonic fans will recognize instantly, such as the Sonic Cheeseburger, Footlong Coney, and Grilled Cheese, all of which still appear on its menu today. The one that really stands out, however, is The Whopper. Burger King opened its first restaurant in 1953, and introduced the Whopper four years later. That means that two of America's favorite fast food chains had an identically named sandwich on their menus at the same time. By all accounts, it wasn't until 1970 that Burger King began trademarking the term "Whopper," meaning the overlap likely carried no legal ramifications.

The one thing the two Whoppers had in common was both believed that size did matter. The history of Burger King's Whopper starts 10 years before the Big Mac, and the name was a reference to the size of the burger. On the other hand, Sonic's Whopper was roughly the size of the catch. Listed as "The Whopper that didn't get away," it's been described on the 1959 Sonic menu as a slab of boneless fish served on a toasted bun with shredded lettuce and tartar sauce.

It's not entirely clear when Sonic discontinued its version of the Whopper, and there is no longer a permanent fish item on the menu. However, the chain occasionally brings back a fish sandwich at select locations during seasonal promotions. When it does return, it's a hit with customers. Instead of a slab of boneless fish, Sonic's modern version features a panko-crusted Alaskan pollock filet served on a warm brioche bun with pickles, lettuce, and creamy tartar sauce.

"It is only available during Lent, which is unfortunate because it is, by far, the best thing on their menu," one fan wrote on Reddit. Another echoed the praise with more detail: "The fish sandwich at Sonic is so slept on. Delicious and always fresh with high-quality flaky white fish."

While The Whopper at Sonic didn't result in any kind of legal issues, there was another case back in the day when Burger King couldn't put Whopper on its original San Antonio menu — because a Texan fast food chain held the trademark for the name "Whopper Burger" in that area.