Before the widespread use of Luna marble beginning in the 1st century BCE, Italic temple decoration was dominated by brightly painted terracotta sculpture. This body of material has been surprisingly neglected in scholarship on Republican art, but has much to tell us about the visual culture of towns, as well as how communities chose to represent themselves in the face of sweeping changes brought on by Roman military expansion. Focusing on the case studies of Cosa and Minturnae in the last three centuries BCE, this dissertation uses architectural terracottas to address broader questions of colonial processes and changing religious landscapes in Republican central Italy. New towns used temple decoration to make particular claims about their identity, longevity, and role within the region. This information rarely survives in textual sources of this period, but can be traced through detailed examination of material remains such as architectural terracottas. I argue that colonial communities drew consciously from local pre-Roman traditions in terracotta in order to give their temples the appearance of being older and more integral to the sacred landscape than was actually the case. Given the heterogenous nature of colonial populations in this period, no single group identity could be easily imported into new foundations. In the absence of defined mythic traditions and cultural memories, colonists used architectural terracottas as part of a broader process of tradition-invention aimed at the creation of group identities. The cultural concerns with archaizing and traditionalism to which these terracottas attest were then carried forward into the ideological and literary discourses of the Early Empire.