National Mac and Cheese Day is observed every July 14 worldwide, celebrating one of America's most beloved comfort foods, macaroni and cheese. This dish, which consists of cooked macaroni and a cheese sauce, has its roots in 14th-century pasta and cheese casseroles found in medieval cookbooks. The modern recipe was introduced to the United States by Thomas Jefferson, who served a version at a state dinner in 1802. Originally a dish for the upper classes, macaroni and cheese became more accessible by the end of the 19th century, especially after Kraft Foods launched boxed mixes in 1937. Today, people celebrate by indulging in mac and cheese, experimenting with various recipes, cheeses, and toppings, and sharing their culinary creations on social media with the hashtag #NationalMacAndCheeseDay.