President Franklin D. Roosevelt put it bluntly, if privately, in 1942-the United States was "a Protestant country," he said, "and the Catholics and Jews are here under sufferance."

In Tri-Faith America, Kevin Schultz explains how the United States left behind this idea that it was "a Protestant nation" and replaced it with a new national image, one premised on the notion that the country was composed of three separate, equally American faiths-Protestants, Catholics, and Jews. Tracing the origins of the tri-faith idea to the early twentieth century, when Catholic and...