Thomas Edison State University moved into downtown Trenton in September 1979, at a time when other institutions were leaving cities. The 7-year-old university, which had spent three years at the Forrestal Center outside of Princeton, needed room for growth. At the same time, the state was looking for an appropriate tenant for the landmark Kelsey Building located adjacent to New Jersey's State House complex and the State House historic district, while the city sought to preserve the building's historic use as a school. Behind the Kelsey Building and the adjoining five restored mid-19th-century brick Townhouses is Petty's Run, which flows to the Delaware River. In the early 1730s, Petty's Run powered a plating mill, and by midcentury drove a steel furnace.