Chciago area remained territory granted to Native Americans, Potowatomies, until 1836, only following the 1832 Blackhawk War--making it one of the last major U.S. metropolitan areas to be founded, following St. Louis, San Francisco, and Los Angeles.  Fort Dearborn was destroyed after the Battle of Fort Dearborn, 1812, and then rebuilt by the U.S. in 1816.  This is an account by a member of the Potowatomi nation that counters that of Mrs. Kinzie invher duaghter-in-law Juliet Kinzie's 1855 novel/travel narrative, Waubun. 

Related to this is a segment of log from the walls of the second Fort Dearborn (1816) blockhouse, the last part demolished, when it was taken down in 1857: http://www.lakeforest.edu/library/archives/indexes/fortdearbornlog.php