Celebrate Chicago's 177th birthday the way you'd want to celebrate your own: with music, good food and free cake. The Mardi Gras-themed celebration kicks off at 10:30 a.m. in Daley Plaza with free Eli's Cheesecake and a happy birthday song. From 11 a.m.-7 p.m., some of the city's favorite food trucks will circle up to sell their wares, including Bridgeport Pasty, Jerk and Flirty Cupcakes.