Westmont is a village in DuPage County, Illinois, United States. Westmont is a community of 5.03 square miles in area. Westmont had a 2010 population of 24,685. It is located approximately 18 miles (29 km) west of the Chicago Loop in the southeastern portion of DuPage County.
The area known as Westmont was inhabited by the Potawatami until the year 1833. After several failed attempts by the U.S. government to persuade the Native Americans to move from the area, in 1833, the Native Americans agreed under coercion to vacate their land for nominal payment.
The development of the Illinois-Michigan Canal, authorized by the State of Illinois in the 1820s but delayed in construction until the 1830s, contributed to Westmont's early growth. When the economic Panic of 1837 halted canal construction, many of the workers turned to farming, and agriculture became the major occupation, with produce sold in nearby Chicago. The area around Westmont became one of the most prosperous sections of the state.
In order to transport agricultural products into the city of Chicago, construction of a plank road originating in Chicago began in 1840. The plank road was placed over the nine-mile (14 km) swamp separating Chicago and the area that became Westmont, and reached Naperville, Illinois by 1851. Today, this roadway is known as Ogden Avenue (U.S. Route 34).