HDC's YouTube channel[1] provides a large catalog of free walking tour videos, Preservation School classes, conference panels, and other educational programming.

HDC was founded in 1970 as a committee of the Municipal Art Society consisting of a coalition of community groups from the designated historic districts of New York City (of which there were then only 14), to serve as their representative, and to advocate for more support for the newly created Landmarks Preservation Commission.

In New York City, HDC is the only advocate for designated historic districts and for neighborhoods meriting preservation in all five boroughs.

[4] HDC also helps promote historic districts[5] and holds annual conferences on topics related to preservation.

Listing on these Registers often helps move the designation process forward at the Landmarks Preservation Commission.