This cross-denominational study explores the relationship between religion, wealth, and social status among the upper class in Philadelphia from the closing decades of the nineteenth century to the onset of the Great Depression. It examines church responses to affluence, describes the religious beliefs that guided members of the upper class, and explores the influence wealthy individuals had within their local churches and broader denominations, particularly through their involvement in congregational formation, church governance, philanthropy, and architectural patronage. In return for their outward commitment to religious principles, wealthy individuals obtained the spiritual capital necessary to secure social status and strengthen class identity. Those who used their financial influence to transform the local religious environment helped lay the foundation for the ascendancy of a national religious establishment that upheld mainline Protestantism as the religious arbiter for the nation. This research advances our understanding of American social and religious history in the modern era by revealing the prevalence and potency of religious belief among members of the upper class, and by giving heed to the ways in which social class affected religious institutions and their mission.