I use repeated cross‐sectional survey data spanning the years 1974 to 2010 to examine changes in Americans’ views of prayer and reading the Bible in public schools. Results from logistic regression models show that support for prayer and reading the Bible in public schools was relatively high in the 1970s and that differences between evangelical Protestants and both Catholics and mainline Protestants grew from the 1970s to the first decade of the twenty‐first century. Hierarchical age‐period‐cohort models demonstrate that changes in support for school prayer are due to both period and birth cohort changes, that baby boom cohorts are relatively likely to oppose prayer and reading the Bible in school, and that growing differences in support for prayer and reading the Bible in school between evangelical Protestants and both Catholics and mainline Protestants are predominantly due to changes across birth cohorts. Although religious liberals and conservatives have become more alike in many ways, evangelical Protestants have diverged from affiliates of other major religious traditions in their support for prayer in public schools. These results are relevant to debates regarding the social impact of religious affiliation, generational differences, and Americans’ views of the role of religion in the public sphere.