Fort Dearborn was a United States fort built in 1803 beside the Chicago River , in what is now Chicago , Illinois . It was constructed by troops under Captain John Whistler and named in honor of Henry Dearborn , then United States Secretary of War . The original fort was destroyed following the Battle of Fort Dearborn during the War of 1812 , and a second fort was reconstructed on the same site in 1816 . By 1837 , the fort had been de-commissioned . Parts of the fort were lost to both the widening of the Chicago River in 1855 , and a fire in 1857 . The last vestiges of Fort Dearborn were destroyed in the Great Chicago Fire of 1871 . The site of the fort is now a Chicago Landmark , located in the Michigan – Wacker Historic District
Great Chicago Fire
Great Chicago Fire
Fort Dearborn