James Thompson

James Thompson (1789 – October 6, 1872) was an American surveyor who created the first plat of Chicago. Born in South Carolina, Thompson moved to Kaskaskia in southern Illinois as a young man and lived in the area for the rest of his life, working primarily as a surveyor. He was hired to plat settlements at the ends of the proposed Illinois and Michigan Canal in northern Illinois; he completed the plat of Chicago, the settlement at the eastern end, on August 4, 1830. After completing his survey of Chicago he returned to the Kaskaskia area and declined an offer of land in Chicago in favor of a cash payment. In addition to his surveying work, he served in various positions such as probate judge, county commissioner, and officer in the Illinois militia during the Black Hawk War.

Chicago appears on maps from the 17th century and had been inhabited by non-indigenous people since the late 18th century. Thompson's plat fixed the location associated with the word "Chicago", which had previously been used for various places around the southwestern shore of Lake Michigan, and allowed the residents of the area to obtain legal title to their property. Extensions of Thompson's plat were made in the following years as Chicago experienced rapid expansion. Chicago incorporated as a town in 1833 and as a city in 1837 as growth continued, and by 1890 had more than a million inhabitants and was the second-most-populous city in the United States. Thompson has been commemorated several times in Chicago's history; his grave, which was originally unmarked, was given a monument by the city of Chicago in 1917.

Early life James Thompson was born in 1789 in Abbeville, South Carolina, to Mary Glasgow and John Porter Thompson. His parents were Scots-Irish immigrants who had moved to the area prior to the American Revolution. Members of the Scots-Irish community in Abbeville created a settlement near Kaskaskia in Randolph County, Illinois, in 1802. Two of Thompson's uncles moved to the settlement in 1804, followed by Thompson and a brother in 1814. Thompson served as a teacher in Kaskaskia for three years before marrying his cousin Margaret in October 1817 and thereafter living in nearby Preston. The couple would ultimately raise 12 children.

Career Early career Thompson surveyed the Kaskaskia and Covington Road in 1819, linking Randolph County to St. Clair and Washington counties. an area of about . It did not extend to Lake Michigan because Fort Dearborn, which had been built by the United States government in 1803, occupied land on the lakeshore. Lake Street was named as it was felt to be the likeliest street to first reach Lake Michigan due to its position near the Chicago River just south of the fort. was used to refer to several locations in the area, such as the modern Chicago River and the modern Des Plaines River. and the plat was extended starting in 1834. The plat and its grid represented the commodification of land in the city that would define its 19th-century development; the grid combined with the advent of balloon-frame construction fueled Chicago's rapid growth. Chicago's expansion was bolstered in the mid-19th century as it became a transportation hub for the United States, and by 1890 it had over a million residents and was the second-most-populous city in the United States.

The intersection of State and Madison Streets was selected as the origin of Chicago's address system in 1909 because they were the baseline of Thompson's plat. The original copy of the plat is held by the Chicago History Museum, to whom it was donated by P. W. Kunning of the Chicago Association of Commerce and Industry in 1954. The Block 37 development in the Chicago Loop is named after one of the numbered blocks in Thompson's plat.

Thompson's grave was originally unmarked.