He was a lifelong friend and business associate of noted botanist William Darlington and was a founder and chief cashier of the National Bank of Chester County.

He studied elementary math and English at a local country school and became a clerk in the office of the Register and Recorder of Chester County in 1810.

The Townsend couple had seven children: Washington, Benjamin Franklin, Priscilla Ann (who died in childhood), Gulielma Maria, Albert, Anna Eliza, and S. Sharpless.

[2][7][8] Townsend corresponded with other botanists across America and Europe, including John Torrey, Francis Boott, and William Jackson Hooker, who named a genus of flowering plants related to the asters Townsendia in his honor.

[4] In 1826, Townsend co-founded the Chester County Cabinet of Natural Sciences and served as the association's treasurer and secretary until his health failed.

[12] Cared for as part of the University library's special collection, and today it is called the Darlington Herbarium (Index Herbariorum code DWC).