The origins of site-based, participatory commemorative art in America began in the mid-twentieth century as a response to traditional representational memorials, empty modernist formalism, and a growing desire for the public commemoration of the countrys significant history, leaders, and events. The aesthetics of these experiential memorials were influenced by the form, as well as the conceptual and rhetorical qualities, of contemporary outdoor sculpture, architecture and landscape architecture and their emphasis on environmental art, site-specific sculpture and earthworks. This mid-twentieth century postmodern commemorative art provided the aesthetic and political foundation for the Vietnam Veterans Memorial and the proliferation of participatory memorials in the 1980-90s. This thesis examines late-twentieth century American participatory commemorative art as a distinct and significant cultural resource brought about by the unique socio-cultural values inherent in public commemoration, experience-based aesthetics and the inclusivist political ideology of its era.