On March 4, 1837, Chicago officially became a city, first mayor William B. Ogden presiding. Fast forward 171 years later, and we're still kicking. In honor of our fine city's birthday, the Chicago History Museum is throwing a party tomorrow complete with Eli's cheesecake, Chicago style hot dogs, the Chicago Children's Choir, and "historical re-enactors". Admission to the museum is free between 9:30 a.m. and 1 p.m. Also if tomorrow happens to be your birthday,......