Religion may well still be the most powerful--yet seriously unexamined--force in American public life. Two centuries ago the U.S population was predominantly white, from the United Kingdom, and Protestant Christian; today America is multicultural, multiracial, and less than 50% Protestant. Yet, uniquely among advanced nations, Americans still remain highly religious -- over 90% affirm their belief in god. Moreover, amidst its diversity, distinct and stable religious/cultural/racial/regional "blocs" persist, with patterns of beliefs and values that influence everything from where we live and whom we marry, to our policy debates and our presidential choices. "Why?" and "how?" are the questions we'll try to answer. We'll look at America's migration and settlement patterns, why some denominations have grown while others have declined, and how issues -- from 19th century struggles over slavery's abolition, temperance, public education, and women's suffrage, right on up to today's fiercely-fought quarrels about homosexuality, abortion, welfare reform, economic justice, and the environment-- have been (and are being) consciously and unconsciously shaped by Americans' religious identities and values. We'll also examine whether, with the sudden recent rise of the “nones”, that history of religion's influence is coming to an end -- and why and what might replace it. Whether you plan a career in public life -- or just want to understand more deeply what shapes our public debates -- this course opens up a "hidden" side of America's history, politics, and economic, social, and cultural relations in ways that few Americans themselves understand.