The presence of a westward‐moving frontier of settlement shaped early U.S. history. In 1893, the historian Frederick Jackson Turner famously argued that the American frontier fostered individualism. We investigate the “frontier thesis” and identify its long‐run implications for culture and politics. We track the frontier throughout the 1790–1890 period and construct a novel, county‐level measure of total frontier experience (TFE). Historically, frontier locations had distinctive demographics and greater individualism. Long after the closing of the frontier, counties with greater TFE exhibit more pervasive individualism and opposition to redistribution. This pattern cuts across known divides in the United States, including urban–rural and north–south. We provide evidence on the roots of frontier culture, identifying both selective migration and a causal effect of frontier exposure on individualism. Overall, our findings shed new light on the frontier's persistent legacy of rugged individualism.

This article explores the foundations of religious influence in politics and society. We show that an important Islamic institution fostered the entrenchment of Islamism at a critical juncture in Indonesia, the world’s largest Muslim country. In the early 1960s, rural elites transferred large amounts of land into waqf—inalienable charitable trusts in Islamic law—to avoid expropriation by the state. Regions facing a greater threat of expropriation exhibit more prevalent waqf land and Islamic institutions endowed as such, including mosques and religious schools. These endowments provided conservative forces with the capital needed to promote Islamist ideology and mobilize against the secular state. We identify lasting effects of the transfers on the size of the religious sector, electoral support for Islamist parties, and the adoption of local sharia laws. These effects are shaped by greater demand for religion in government but not by greater piety among the electorate. Waqf assets also impose costs on the local economy, particularly in agriculture, where these endowments are associated with lower productivity. Overall, our findings shed new light on the origins and consequences of Islamism.

This article shows how the migration of millions of Southern whites in the twentieth century shaped the cultural and political landscape across the United States. Racially and religiously conservative, Southern white migrants created new electoral possibilities for a broad-based coalition with economic conservatives. With their considerable geographic scope, these migrants hastened partisan realignment and helped catalyze and bolster a New Right movement with national influence over the long run. More than just augmenting the conservative voter base outside the South, they influenced non-Southerners by building evangelical churches, diffusing right-wing media, and mixing through intermarriage and residential integration. Tracking non-Southern households, we show that exposure to Southern white neighbors increased adoption of conservative religious norms. Overall, our findings suggest that this mass migration blurred the North–South cultural divide and reshaped the geography of conservatism in the United States.

This paper develops a new framework for understanding when and how migrants shape culture, applying it to the Confederate diaspora—a small migrant group that left a large cultural imprint. Southern Whites that migrated after the Civil War played a pivotal role in spreading Confederate symbols and racial norms across the U.S. by the early 20th century. Their far-reaching influence stemmed from two key conditions: (i) an ideological intensity rooted in their experiences of slavery, secession, and military defeat and (ii) access to malleable power structures during westward expansion and post-war reconciliation. These conditions enabled them to transmit Confederate culture to both kin and non-Southern neighbours and to expand their reach by mobilising civil society organisation and leveraging positions of authority. They shaped policies and institutions that helped entrench racial norms and inequalities in labour markets, housing, and the criminal justice system. Our findings provide empirical foundations for understanding how migrants can transform local culture, rather than merely assimilate.

We use a population resettlement program in Indonesia to identify long-run effects of intergroup contact on national integration. In the 1980s, the government relocated two million ethnically diverse migrants into hundreds of new communities. We find greater integration in fractionalized communities with many small groups, as measured by national language use at home, intermarriage, and children’s name choices. However, in polarized communities with a few large groups, ethnic attachment increases and integration declines. Residential segregation dampens these effects. Social capital, public goods, and ethnic conflict follow similar patterns. Overall, our findings highlight the importance of localized contact in shaping identity.