When the Brandywine Valley was in danger of being developed in the 1960s, a few locals raised enough money to purchase the land, and founded in the Brandywine Conservancy. Then in 1971, the Conservancy opened the Brandywine River Museum—now known as the Brandywine Museum of Art—in the renovated Hoffman’s Mill, a former gristmill built in 1864 that was part of the Conservancy’s first preservation efforts.