The traditional model of National Park development in the United States relied on federally owned public domain lands, leaving the original thirteen eastern states without significant federal parklands. In response, innovative strategies were developed in the mid-20th century to address this gap. The establishment of the Cape Cod National Seashore in 1961 marked a turning point, as it was the first National Park created through fee simple land purchases and allowed for the inclusion of private homes. This led to the creation of the Cape Cod National Seashore Advisory Commission, which served as a collaborative mechanism between federal, state, and local entities, pioneering new approaches to zoning, land acquisition, and community engagement. These methods proved successful and were later adopted in the creation of other parks, such as the Lowell National Historical Park. Despite differing missions—preserving natural versus urban historic resources—both parks represent a shift in National Park Service policy to accommodate the unique challenges of non-public domain states through innovative and adaptive planning.