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 swamp separating Chicago and the area that became Westmont, and reached Naperville, Illinois by 1851. Today, this roadway is known as Ogden Avenue. The plank road soon became inadequate; in 1858, local incorporated towns and villages petitioned the Chicago, Burlington and Quincy Railroad to build a branch line from Chicago to Aurora, Illinois that would pass through their towns. The railroad line was approved, with the first train in 1864. "Greg's Station," from which Westmont developed, was a stop to load agricultural and dairy products. The town transitioned gradually from an agricultural community to a commuter community, with the early growth and development centered around the railroad station. In the early 1900s, plats for the Village of Westmont were laid out and roads were dedicated; incorporation, decided by a vote of 41-28 , followed in 1921. Westmont was officially incorporated on November 4, 1921; Vince Pastor served as the first president of the Village Board.
As of the special census of 2007, there were 26,211 people, 9,900 households, and 5,979 families residing in the village. The population density was 5,014.4 people per square mile. There were 10,269 housing units at an average density of 2,097.1 per square mile. The racial makeup of the village was 78.02% White, 5.38% African American, 0.13% Native American, 11.95% Asian, 2.41% from other races, and 2.11% from two or more races. Hispanic or Latino people of any race comprised 6.98% of the population. There were 9,900 households; 29.1% of these households had children under the age of 18 living with them. 47.1% were married couples living together, 10.4% had a female householder with no husband present, and 39.6% were non-families. 32.5% of all households were made up of individuals and 11.8% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 3.05. The population was spread out with 21.9% under the age of 18, 8.3% from 18 to 24, 33.8% from 25 to 44, 20.3% from 45 to 64, and 15.7% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 87.4 males. For every 100 females age 18 and over, there were 82.9 males. The median income for a household in the village was $51,422, and the median income for a family was $64,472. Males had a median income of $42,909 versus $33,690 for females. The per capita income for the village was $26,394. About 3.8% of families and 5.8% of the population were below the poverty line, including 4.8% of those under age 18 and 8.5% of those age 65 or over.
