A suspicion toward inherited notions of agency has long been recognized (and frequently decried) as a defining feature of literary naturalism. But while the deterministic worldview of writers like Theodore Dreiser generated much lively debate in the early twentieth century, literary scholarship’s investment in the unresolved (and perhaps unresolvable) questions of inanimate agency raised by such works was gradually eclipsed by other concerns. Recently, however, a vigorous interest in such metaphysical questions has resurfaced in the discourse of new materialism, an interdisciplinary and politically committed field of scholarship dedicated to revising humanity’s conventional associations of materiality with passivity and predictability. While this is ostensibly a “new” movement, placing new materialism in the context of American literary history underscores how old—or rather timeless—the concerns addressed by the new materialism really are. Given these similarities, Trumpeter proposes that new materialist discourse stands to profit from a more nuanced understanding of literary naturalism and the discourse of new materialism can likewise help American literary scholars return to naturalist works with a more refined and reenergized perspective on the genre’s perennial concerns. This essay examines the role of the inanimate in Sister Carrie and An American Tragedy as a means for tracing connections and highlighting divergences between these two intellectual movements engaged in drawing humanity’s attention to the surreptitiously active nature of things.