The Bridge in Williams Township, Jacob Arndt House and Barn, Coffeetown Grist Mill, and Isaac Stout House, all in the township, are each listed on the National Register of Historic Places.

Morgan Hill is a census-designated place in the northeastern part of the township.

As of the 2000 census,[5] there were 4,470 people, 1,657 households, and 1,267 families residing in the township.

18.4% of all households were made up of individuals, and 7.0% had someone living alone who was 65 years of age or older.

[6] Interstate 78 follows an east-to-west alignment in the northern part of Washington Township.

The western end of the Interstate 78 Toll Bridge, which crosses the Delaware River to Phillipsburg, New Jersey, is located in Williams Township.

Route 611 follows a north-south alignment along the Delaware River from Martins Creek via Easton to Kintnersville.