Shake Shack is an American fast casual restaurant chain based in New York City. It started out as a food cart inside Madison Square Park in 2004, and its popularity steadily grew. It eventually moved to a stand within the park, expanding its menu from New York-style hotdogs to one with hamburgers, hotdogs, fries and its namesake milkshakes. The company prides itself and emphasizes its use of all-natural 100% angus beef only and that its meat has no hormones nor antibiotics.