American Aurora explores the role of environmental knowledge in the radical Protestant discourses of the mid-Atlantic in the seventeenth and eighteenth centuries. This exploration occurs primarily through the person and legacy of Johannes Kelpius (1667-1708), a transatlantic ascetic and esoteric figure who has largely confounded generations of historians and scholars. By engaging long-neglected archives of vernacular religious literature and esoteric forms of religious thought and practice, my dissertation explores how radical Protestant practices of attending to extraordinary environmental phenomena during the dramatic climatic shifts of the seventeenth century shaped early American religious and political attitudes during the colonial period. As my analysis continues through the Enlightenment and approaches the turn towards historical knowledge at the end of the eighteenth century, I conclude that Enlightenment disciplines of knowledge have obscured the historical memory of Kelpius and the ability of contemporary scholars to adequately understand early modern Protestant practices of environmental knowledge.