1671
"Chicagou at the Lower End of Lake Michigan" is first mentioned in a report by Father Pierre Charlevoix.

1673
May-September: Jacques Marquette and Louis Joliet's exploration of the Mississippi River and Lake Michigan takes them by the future site of Chicago. Joliet reports that a canal connecting Lake Michigan to the Mississippi at this point would control the entire known North American continent.

1674
December: Marquette returns to Chicago. Within 6 months, he will die of dysentery.

1763
With the end of the French and Indian War, Great Britain takes control of all North America east of the Mississippi, including the Chicago area.

1778
Virginia claims land along the Mississippi River as the "County of Illinois."

1784
Virginia grants Illinois to the United States as payment for debts incurred during the Revolutionary War.

1784-1788
Sometime during these years, fur trader Jean Baptiste Point du Sable becomes the first settler in the Chicago area.

1803
Secretary of War Henry Dearborn orders a survey of the Chicago River to find a site suitable for a military post. Fort Dearborn is established near the mouth of the river by year's end. Five families own homes in the town.

1809
February 9: Chicago becomes part of the Territory of Illinois.

1812
Before the war, 15 private homes exist in Chicago; after war is declared and Fort Dearborn is taken by the British, only four will remain.

1818
December 3: Illinois becomes the 21st state in the union.

1831
January 15: the Illinois General Assembly creates Cook County, with Chicago as the county seat.

1833
August: the Town of Chicago is incorporated. The population totals no more than 200 people.

1836
William Butler Ogden comes to Chicago to make his fortune. He had first visited the town a year earlier while administrating a land purchase made by his brother-in-law.

1848
Cyrus McCormick relocates his harvesting machine factory to Chicago, closer to the breadbasket of the nation.

1854
Cholera kills 60 residents every summer day in Chicago. Six percent of the city's human population dies from the disease, spread through polluted water.

1855
The town begins to construct a public sewer system.

1856
The first University of Chicago is founded.

1859
George Pullman arrives to run a business that lifts buildings to the level of the new sewers.

1860
May 18: The Republican Party nominates Illinois lawyer Abraham Lincoln as its candidate for the presidency in Chicago.

1868
A field is built for the Chicago White Stockings baseball team. The Chicago ball club is quite successful in the 19th century. Later, they adopt a nickname given them in the local papers and change their name to the Cubs.

1871
July 18: In a stupendous feat of engineering (and with utter disregard for southern neighbors), engineers reverse the Chicago River's direction. Instead of carrying the city's waste into Lake Michigan, the source of the city's drinking water, the polluted water flows south toward the Mississippi. After a year, the river will stall and returns to static sludge.

October 8: The Great Fire starts at 9 o'clock Sunday night and burns until early Tuesday morning, October 10th. The history of Chicago and the life stories of 19th century Chicagoans will henceforth be demarcated as "before the Fire" and "after the Fire."

1877
Summer: Chicago emerges as a center of labor agitation during a general strike of railroad workers. On July 26, workers from a variety of industries, many of them immigrants and socialists, riot in the streets, battling police and U. S. militia. The rioters seek an eight-hour work day and the restoration of slashed wages. The Great Uprising, as it is called, results in the deaths of 100 workers nationwide, 30 of them in Chicago. No Chicago police are killed or seriously injured. The uprising marks the beginning of a cycle of class warfare and labor violence in the United States, and Albert Parsons's emergence as a labor leader.

1880
After buying out his previous partners, Marshall Field becomes the sole proprietor of the most elegant store in Chicago, Marshall Field and Company.

1882
Charles L. Hutchinson and others found the Art Institute of Chicago. Society queen Bertha Palmer later donates her extensive collection of Impressionists paintings to the institute.

1885
William LeBaron Jenney's Home Insurance Building uses, for the first time, an iron skeleton construction for support, leading to the development of the Chicago School skyscraper.

1886
May 3: A strike at the McCormick reaper factory turns violent. Police kill two workers.

May 4: A demonstration is held at Haymarket Square protesting the deaths of the day before. As it winds down, police enter the square and a bomb is thrown at them. Shooting ensues. Seven policemen are killed and more than fifty are injured.

June 21: Eight men stand trial as accessories to murder for the Haymarket affair. No one is accused of actually throwing the bomb. All are found guilty.

1887
The Marshall Field Warehouse, designed by Henry Hobson Richardson, is completed a year after the death of its architect.

November 11: Four of the eight Haymarket defendants are hung (of the others, two asked for clemency and received life sentences, one was sentenced to fifteen years, and one committed suicide in jail).

1889
Jane Addams and Ellen Gates Starr open Hull-House, a settlement house offering educational and practical social services to immigrants and the working poor.

Dankmar Adler and Louis Sullivan's Auditorium Building is completed. Sullivan makes his architectural reputation; his assistant Frank Lloyd Wright flushes out most of the interior design drawings; and Chicago has a world-class stage for cultural performances.

1890
Aaron Montgomery Ward begins his protracted legal battle to keep the lakeshore "Public Ground -- A Common to Remain Forever Open, Clear, and Free of Any Buildings, or Other Obstruction, Whatever." In 1909, the Illinois Supreme Court will support his position.

1891
Theodore Thomas arrives in Chicago to head the Chicago Orchestra. Its first home is in the Auditorium Building.

1892
October 1: Opening day of the new University of Chicago with William Rainey Harper as its president.

1893
May 1-October 30: Chicago hosts the World's Columbian Exposition. Twenty-seven million people visit the fair.

June: A monument to the Haymarket defendants is erected in Waldheim Cemetery. The living defendants are given an unconditional pardon and the trial is denounced by the new governor.

October 28: As the Exposition draws to a close, a madman murders the popular mayor Carter Harrison in his home.

1894
May 12: Workers at the Pullman factory go on strike, led by labor organizer and future presidential nominee Eugene Victor Debs. The strike will be broken by federal troops, but Pullman's behavior is so odious that his reputation is ruined even among fellow capitalists.

1894
July 5: The Exposition site burns down.

1897
October 18: George Pullman dies.

1898
The town of Pullman is divested from Pullman's company.

1900
January 2: The Chicago Sanitary and Ship Canal flows from Lake Michigan to the Mississippi. The Chicago River is forever reversed and Joliet's dream -- to effectively connect the Great Lakes with the Mississippi River — is complete.