Designated a National Historic Landmark in 1962, the park is currently managed by the Central Park Conservancy under contract with the city government. The Conservancy is a non-profit organization that contributes 83.5% of Central Park's $37.5 million annual budget, and employs 80.7% of the park's
maintenance staff.Central Park was not a part of the Commissioners' Plan of 1811; however, between 1821 and 1855, New York City nearly quadrupled in population. Since it was not part of the Commissioners' Plan of 1811, John Randel, Jr., surveyed the park and the only remaining surveying bolt from his survey is still visible. The bolt is in a rock just north of the Dairy and the 65th Street Transverse and south of Center Drive. As the city expanded, people were drawn to the few existing open spaces, mainly cemeteries, to get away from the noise and chaotic life in the city.