13 South William Street

Listed on the

National Historic Register,

this building was built in 1837-1839.

In 1903 architect C.P.H. Gilbert

converted it into its current

Neo-Dutch Renaissance style.

Today the building is home to

America's oldest security agency,

McRoberts Protective Agency, Inc.,

which was founded in downtown

Manhattan in 1876.

Marker is on South ...