Alexandria Township municipal offices are located at 21 Hog Hollow Road, Pittstown NJ 08867; phone: 908-996-7071.
The township is named for James Alexander, an early landowner.
Alexandria is home to the National Register's Mount Pleasant Historic District. Mt. Pleasant is located in Alexandria and Holland Townships along a branch of the Hakeahawka Creek. Early mills spurred the growth of the village that in 1881 had a post office, two stores, a mill, blacksmith and wheelright shops, and a Presbyterian Church.