Thornbury Township was organized in 1687 with the appointment of Hugh Durborrow as constable and received its name from Thornbury, in Gloucestershire, England. At the time, no more than five or six families lived within the limits of the township. George Peirce, one of the earliest and most influential inhabitants of the township, was married to a native of Thornbury, England, and the township was purportedly named to compliment her. Thornbury, Birmingham and Westtown townships are the only townships within the present limits of Chester County which were organized before 1704. The township was divided when Delaware County was separated from Chester County in 1798. As a result, there is a Thornbury Township in each county. Landowners were allowed to choose which county they wished to be in, causing the line between the two townships, and the two counties, to be very irregular. The Battle of Brandywine, part of the American Revolutionary War took place partially in the town. It was one of Thornbury's citizens, Squire Thomas Cheyney, who informed George Washington, commander of the Continental Army, of the approach of the British troops. The Squire Cheyney Farm and William J. Barnard Residence are listed on the National Register of Historic Places.
Points of interest
Entries in the National Register of Historic Places
At the 2010 census, the township was 85.5% non-Hispanic White, 3.4% Black or African American, 0.1% Native American, 7.6% Asian, and 1.4% were two or more races. 1.9% of the population were of Hispanic or Latino ancestry. As of the census of 2000, there were 2,678 people, 1,023 households, and 734 families residing in the township. The population density was 684.8 people per square mile. There were 1,095 housing units at an average density of 280.0/sq mi. The racial makeup of the township was 91.90% White, 2.58% African American, 4.56% Asian, 0.04% Pacific Islander, 0.22% from other races, and 0.71% from two or more races. Hispanic or Latino of any race were 0.78% of the population. There were 1,023 households, out of which 33.6% had children under the age of 18 living with them, 65.6% were married couplesliving together, 4.2% had a female householder with no husband present, and 28.2% were non-families. 22.6% of all households were made up of individuals, and 3.0% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.10. In the township the population was spread out, with 26.0% under the age of 18, 5.4% from 18 to 24, 34.8% from 25 to 44, 26.7% from 45 to 64, and 7.2% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 95.6 males. For every 100 females age 18 and over, there were 95.6 males. The median income for a household in the township was $84,225, and the median income for a family was $112,291. Males had a median income of $70,602 versus $42,371 for females. The per capita income for the township was $47,505. None of the families and 1.6% of the population were living below the poverty line, including no people under eighteen, and 2.0% of those over 64.
