The environmental movement remains an understudied aspect of modern American politics. The literature covers some aspects of environmentalism quite well, such as wilderness preservation and water pollution control, but historians have yet to adequately describe the movement as a whole. Historians are still wondering what the environmental movement encompassed. Where should we set the movement's boundaries? Various materials at the Rockefeller Archive Center recommend an inclusive definition, one that accounts for the strong connections among modern environmentalism, historic preservation, and regional planning. These connections become particularly clear in the documents gathered by the Rockefeller brothers as they pursued their interests in the Hudson River. In the post-World War II era, residents in the Hudson Valley expressed growing concern about rapid growth. This concern took the form of multiple conservative movements.