[3][4][5] 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.

[6][7] The Squire Cheyney Farm and William J. Barnard Residence are listed on the National Register of Historic Places.

[8] Entries in the National Register of Historic Places According to the United States Census Bureau, the township has a total area of 3.9 square miles (10 km2), all land.

[18] Elementary schools serving sections include Penn Wood, Sarah Starkweather, and Westtown-Thornbury.

US 202/US 322 concurrently follow the Wilmington-West Chester Pike along a northwest-southeast alignment through the southwestern portion of the township.

PA 926 follows Street Road along a southwest-northeast alignment along the northwest edge of the township.