The history of Hinsdale can be traced back for more than a century. Hinsdale is an example of the upper middle-class railroad suburb that developed across the country from 1850 through 1880. Chicago, with a network of 11 separate railroad lines that entered the city from 1847 through 1861, had more than 100 railroad suburbs surrounding it by 1873. Hinsdale covers an area just under 5 square miles and is defined by Downers Grove Township, with the Cook County portion located in Lyons Township, and the very northern edge of town located in York Township.