Despite present day attitudes and practices in which combinations of photography and other mediums of art are readily accepted, this was rarely the case during the 1960s and 1970s. The pioneering 1970 Museum of Modern Art exhibition Photography into Sculpture, which is the focus of this dissertation, is a compelling exception. Organized by Peter Bunnell, the exhibition highlighted work by twenty-three artists that mixed photographic imagery with three-dimensional forms. The resulting objects often dislocated "straight" photography’s reliance on the image and optical description as its primary source of meaning, characteristics presumed to be fundamental and fixed by many at the time. Bunnell argued that the physicality of the works in Photography into Sculpture made the medium visible and available for critique. This dissertation establishes the archival record and an oral history for the exhibition. It also finds that Bunnell prepared this unorthodox exhibition with John Szarkowski’s endorsement, therefore contradicting enduring views that Szarkowski’s photography program at the Modern promoted a monolithic ideology that did not include experimental modes. Peter Bunnell and Robert Heinecken are the principal figures in Photography into Sculpture. Bunnell, as curator and historian, and Heinecken, as artist and professor of photography at University of California, Los Angeles, were both committed to the idea that the photograph was not only an image but also an object. In public statements they argued that the attention placed on straight photography by many critics and educators discouraged experimentation and excluded an emerging generation of photographers eager to challenge lingering modernist traditions that emphasized the integrity of the image and conventions of display. Both men and their contemporary Nathan Lyons worked from within photography’s established institutions and organizations–including the Museum of Modern Art, George Eastman House, and The Society for Photographic Education–to advocate for alternatives. This dissertation demonstrates that the revolutionary ideas of Bunnell and Heinecken were part of a long rebellion against photographic modernism.