White Castle Is Celebrating National Slider Day By Giving A Free Slider To Every Single Customer

White Castle is offering every customer a free cheese slider on May 15, which marks the restaurant's National Slider Day. But there's a catch. Interested fans will need to present the National Slider Day coupon from the White Castle website to participate in the deal.

Sliders are ubiquitous these days; many people have developed a taste for the tiny but flavorful hamburgers (and assorted other sandwiches). However, even the biggest fans of small sandwiches may be unaware of where this beloved treat originated. According to a May 9 press release, White Castle first introduced the concept in 1921. Since then, White Castle's menu has expanded to include all sorts of slider selections, such as the Panko Fish Slider and the Impossible Slider, which features a plant-based patty. 

The restaurant is so proud of its storied history that it developed National Slider Day to honor its contribution to the fast-food world.

What better way to celebrate the holiday than to pick up some White Castle sliders? Fans are in for a treat, as the chain is using its special day to give back to its devotees (which White Castle lovingly refers to as Cravers). 

All customers who stop by the restaurant on National Slider Day will be privy to a free slider with no purchase necessary. Members of White Castle's free loyalty club, Craver Nation, can also access deals on slider combos and more by visiting the chain's app. 

And in addition to its restaurant offerings, White Castle sells items in grocery stores and other retail establishments. If you want to enjoy White Castle sliders at home, you can also access offers at various locations when you order through Instacart. (The complimentary cheese sliders are only available in restaurants on May 15, however.)