On August 2, 1962, architect Philip Johnson, urban activist Jane Jacobs, and dozens of others picketed outside Pennsylvania Station to protest plans to tear down the 1910 Beaux-Arts masterpiece. Their campaign was the culmination of over a decade of struggle to protect city landmarks. Although they lost the battle over Penn Station, the building’s demolition helped lead to the passage of New York’s 1965 landmarks preservation law.

Following World War II, large swaths of the city were cleared to make way for office buildings, housing complexes, and roads. While some considered this progress, a small but influential group of activists warned of the loss of New York’s cultural and historic heritage. The Municipal Art Society and other groups fought the efforts of developers, including City Construction Coordinator Robert Moses, to tear down “landmark” structures.

But it wasn’t until the Landmarks Preservation Law of 1965 that buildings could be legally protected. Not only did the law allow for the preservation of individual structures, it also became a tool for activists fighting to preserve the character of entire neighborhoods.

The law and its application remain contested topics. Affected property owners often point to the financial difficulties of adhering to the preservation law, and some preservation advocates have complained about insufficient landmark protection. But indisputably, New York activists helped make New York City, in the words of historian Anthony C. Wood, “the intellectual capital of the preservation movement.”