Throughout the late eighteenth and nineteenth centuries the American frontier—the mobile line of settlement—moved from the Eastern Seaboard to the West Coast. In 1890 the US Census Department declared the frontier closed, but, in 1893, historian Frederick Jackson Turner argued that it continued to shape American identity. Current scholarship in Western history and American studies complicates Turner’s thesis, arguing that in addition to being a site of white conquest, the frontier was a space of intercultural contact between diverse Native American groups and Europeans, Africans and Asians. The frontier has functioned powerfully as a contemporary metaphor for social and technological innovation, recalled in John F. Kennedy’s claims for a “new frontier,” and as a mediascape in genres like the western and science fiction.