Fort Dearborn 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 in 1812 , and a new fort was constructed on the same site in 1816 . The fort was de - commissioned by 1837 , and parts of the fort were lost to the widening of the Chicago River in 1855 and a fire in 1857 ; the last vestiges being destroyed in the Great Chicago Fire of 1871 . The site of the fort is now a Chicago Landmark , part of the Michigan – Wacker Historic District . Background . The history of human activity in the Chicago area prior to the arrival of European explorers is mostly unknown . In 1673 , an expedition headed by Louis Jolliet and Jacques Marquette , though possibly not the first Europeans to visit the area , was the first recorded to have crossed the Chicago Portage and travelled along the Chicago River . Marquette returned in 1674 , camped a few days near the mouth of the river , then moved on to the portage , where he stayed through the winter of 1674 – 75 . Joliet and Marquette did not report any Indians living near the Chicago River area at this time , though archaeologists have since discovered numerous Indian village sites elsewhere in the greater Chicago area . Two of La Salle ' s men built a stockade at the portage in the winter of 1682 / 1683 . A Jesuit mission , Mission of the Guardian Angel , was founded somewhere in the vicinity of Chicago in 1696 , but was abandoned in around 1700 . The Fox Wars effectively closed the Chicago area to Europeans in the first part of the 18th century . The first non - native to re - settle in the area may have been a trader named Guillory , who might have had a trading - post near Wolf Point on the Chicago River in around 1778 . Jean Baptiste Point du Sable built a farm and trading post near the mouth of the Chicago River in the 1780s , and he is widely regarded as the Founder of Chicago . Antoine Ouilmette is the next recorded resident of Chicago ; he claimed to have settled at the mouth of the Chicago River in July 1790 . In 1682 , René Robert Cavelier , Sieur de La Salle had claimed a large territory , including the Chicago area , for France . In 1763 the French ceded this area to Great Britain ' s Province of Quebec following the French and Indian War . Great Britain then ceded the area to the United States at the end of the American Revolutionary War , though the Northwest Territory remained under " de facto " British control until 1796 . Following the Northwest Indian War of 1785 – 1795 , the Treaty of Greenville was signed at Fort Greenville ( now Greenville , Ohio ) , on August 3 , 1795 . As part of the terms of this treaty , a coalition of Native Americans and Frontiers men , known as the Western Confederacy , turned over to the United States large parts of modern - day Ohio , and various other parcels of land including six square miles centered at the mouth of the Chicago River . The first fort . On March 9 , 1803 , Henry Dearborn , the Secretary of War wrote to Colonel Jean Hamtramck , the commandant of Detroit , instructing him to have an officer and six men survey the route from Detroit to Chicago , and to make a preliminary investigation of the situation at Chicago . Captain John Whistler was selected as commandant of the new post , and set out with six men to complete the survey . The survey completed , on July 14 , 1803 , a company of troops set out to make the overland journey from Detroit to Chicago . Whistler and his family made their way to Chicago on a schooner called " Tracy " . The troops reached Chicago on August 17 ; the " Tracy " was anchored about half a mile offshore , unable to enter the Chicago River due to a sandbar at its mouth . Julia Whistler , the wife of Captain Whistler ' s son , Lieutenant William Whistler , later related that 2000 Indians gathered to see the " Tracy " . The troops had completed the construction of the fort by the summer of 1804 ; it was a log - built fort enclosed in a double stockade , with two blockhouse s . The fort was named " Fort Dearborn " after Henry Dearborn , the Secretary of War , who had commissioned its construction . The fur trader John Kinzie arrived in Chicago in 1804 , and rapidly became the civilian leader of the small settlement that grew around the fort . In 1810 Kinzie and Whistler became embroiled in a dispute over Kinzie supplying alcohol to the Indians . In April , Whistler and other senior officers at the fort were removed ; Whistler was replaced as commandant of the fort by Captain Nathan Heald . Battle of Fort Dearborn . During the War of 1812 , General William Hull ordered the evacuation of Fort Dearborn in August 1812 . Heald oversaw the evacuation , but on August 15 the evacuees were ambushed by about 500 Potawatomi Indians in the Fort Dearborn Massacre . The Potawatomi captured Heald and his wife , Rebekah , and ransomed them to the British . Of the 148 soldiers , women and children who evacuated the fort , 86 were killed in the ambush . The Potawatomi burned the fort to the ground the next day . The second fort . Following the war , a second Fort Dearborn was built in 1816 . This fort consisted of a double wall of wooden palisade , officer and enlisted barracks , a garden , and other buildings . The American forces garrisoned the fort until 1823 , when peace with the Indians led the garrison to be deemed redundant . This temporary abandonment lasted until 1828 , when it was re - garrisoned following the outbreak of war with the Winnebago Indians . In her 1856 memoir " Wau Bun " , Juliette Kinzie described the fort as it appeared on her arrival in Chicago in 1831 : The fort was closed briefly before the Black Hawk War of 1832 and by 1837 , the fort was being used by the Superintendent of Harbor Works . In 1837 , the fort and its reserve , including part of the land that became Grant Park , was deeded to the city by the Federal Government . In 1855 part of the fort was demolished so that the south bank of the Chicago River could be dredged , straightening the bend in the river and widening it at this point by about ; and in 1857 , a fire destroyed nearly all the remaining buildings in the fort . The fort ' s tower bell was rescued from the remains by Police Constable Jacob Schoenewald and donated for use in the bell tower of St . Joseph ' s Catholic Church during its construction in 1864 . The blockhouse and the few surviving outbuildings were destroyed in the Great Chicago Fire of 1871 . Legacy and monuments . Fort Dearborn was located at what is now the intersection of Wacker Drive and Michigan Avenue in the Loop community area of Chicago at the foot of the Magnificent Mile . Part of the fort outline is marked by plaque s and a line embedded in the sidewalk and road near the Michigan Avenue Bridge and Wacker Drive . A few boards from the old fort were retained and are now in the Chicago History Museum in Lincoln Park . On March 5 , 1899 , the " Chicago Tribune " publicized a Chicago Historical Society replica of the original fort . Also in 1933 , at the Century of Progress Exhibition , a detailed replica of Fort Dearborn was erected as a fair exhibit . As part of the celebration both a United States postage stamp and souvenir sheet ( containing 25 of the stamps ) were issued showing the fort . In 1939 , the Chicago City Council added a fourth star to the city flag to represent Fort Dearborn . This star is depicted as the left - most , or first , star of the flag . The site of the fort was designated a Chicago Landmark on September 15 , 1971 .