The Potawatomi, Ottawa and Ojibwe lived in the Des Plaines River Valley before Europeans arrived. French explorers and missionaries of the 1600s named the river La Riviere des Plaines because its trees resembled European plane trees. The first white settlers came from the eastern United States in 1833, after the Treaty of Chicago, followed by many German immigrants in the 1840s and 1850s.
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In the 1850s the Illinois and Wisconsin Land Company bought land along a planned railroad from Chicago to Janesville, Wisconsin, and in 1852 developers built a steam mill by the river to cut railroad ties. Socrates Rand bought the mill and turned it into a gristmill that drew local farmers, and the railroad made its first stop there in the fall of 1854. On May 22, 1855, the earliest known tornado in Illinois struck at a place reported as Jefferson, now identified as Des Plaines, killing three people in a granite house lifted off its foundation. Joseph Henry of the Smithsonian's correspondence about it with a Chicago newspaper helped lead to the national weather service's earliest predecessor.
The railroad platted a town named Rand near the mill, and after the Chicago and North Western bought the line in 1859 and named its station Des Plaines, the subdivision took that name and was incorporated as a village in 1869, reincorporated in 1873 with the brickmaker Franklin Whitcomb as first village president. In 1925 residents voted to become a city and annexed Riverview, and the city grew rapidly after World War II and the opening of nearby O'Hare Airport.
Sources
Wikipedia: Des Plaines, Illinois