The Historic Districts Council is a New York City nonprofit founded in 1970 as a committee of the Municipal Art Society, formed to organize neighborhood advocates supporting the city's then-new Landmarks Preservation Commission. It became an independent incorporated organization in 1985 and hired its first full-time executive director in 1992. HDC works across all five boroughs, guiding residents and property owners through the landmarking and Landmarks Preservation Commission review processes, monitoring preservation compliance, testifying before city commissions on development proposals affecting historic neighborhoods, and sponsoring applications to state and national historic registers. It has been involved in the creation of the large majority of New York City's more than 150 designated historic districts.