ST. LOUIS — Want a free burger? White Castle is celebrating National Slider Day on May 15 by offering customers a free slider, with no purchase required. Customers can redeem this offer using a digital coupon from White Castle’s social media or by entering the code SLIDERDAY on the app.

“We’re humbled to have always led the charge to serve up hot and tasty food at an affordable price,” states Jamie Richardson, vice president at White Castle. “Today when families follow their Crave to the Castle, no matter their income, they know they are going to be able to explore a delicious menu they can afford. It’s a testament to how we’ve helped create memorable moments for generations of customers.”

White Castle introduced National Slider Day in May 2015. Founded in 1921, White Castle played a significant role in making the hamburger a popular American food.