Assessments on the nature, degree, and source of Mesoamerican influence on social dynamics of pre-Hispanic societies of northern Mexico and the U.S. Southwest has waxed and waned over the past century. Scholars agree that key domesticated agricultural crops, such as maize from Mesoamerica, served to transform the economic and social lifeways of people in the Southwest, with some considering crops alone to be the most significant southern contribution. However, there remains an ongoing debate on characterizing how the political, religious, economic, and social dynamics of Mesoamerican complex societies impacted and intersected with Southwestern social changes, particularly after A.D. 900. Was there synchronicity in these connections? Which specific societies in Mesoamerica were involved and why? In this talk, Mathiowetz aims to reorient and sharpen the focus of this debate by identifying a key geographical locale in Mesoamerica that had an outsized role in shaping historical processes of change among various cultures in the U.S. Southwest and northern Mexico.