American Evangelicalism is a vast and nearly indefinable coalition movement of sometimes competing, sometimes cooperating denominations and independent churches whose ideological boundaries have been shifting since its postwar reemergence. On the Boundaries of American Evangelicalism seeks to account for the emergence of this coalition of moderate Protestants in the 1940s and 1950s as distinct from fundamentalism on the right and liberalism on the left and speculate on the reasons for the fracturing and decline of that coalition in the 1960s to the 1990s.