Val-Kill became the property of the National Park Service in 1977 when President Jimmy Carter signed legislation creating the Eleanor Roosevelt National Historic Site.

ER did not expect her property to become a national treasure. She left the retreat to her son John in her will and when he moved out of Stone Cottage in 1965, the family had ER's home divided into four apartments. In 1970, two physicians purchased the property from John Roosevelt and in 1972 they appealed to the Hyde Park Town Council for a zoning variance so they could convert Val-Kill into a planned community for senior citizens. They asked for permission to build a health care facility, a nursing home and free standing housing units for the elderly. The council rejected the doctors' request. In 1975, women members of the Hyde Park Visual Environment Committee, the director of the Franklin D. Roosevelt Library, Curtis Roosevelt and other family members, the actress Jean Stapleton, and representatives for the state attorney general's office formed a coalition to prevent commercial development at Val-Kill and to have the site preserved as a memorial to ER. Seven years later and one hundred years after her birth, the Eleanor Roosevelt National Historic Site opened to the public. In 1999, First Lady Hillary Rodham Clinton designed the site an American Treasure.