Did you ever wonder how “In God We Trust” came to be quoted on every American coin and dollar bill? Or why the Pledge of Allegiance to the most revered symbol of the nation includes an explicit declaration of confidence in the Almighty? Or why the president and members of Congress host a National Prayer Breakfast the first Thursday of each February?

These now utterly commonplace markers of public piety were almost all created during the same decade — the 1950s. Their initial enthusiasts, as described by the Princeton historian Kevin M. Kruse, were conservative Protestant ministers and businessmen who hoped Americans would not take their handiwork for granted. They believed the nation badly needed a religious awakening to reverse the depredations of a godless federal state.

“Every Christian should oppose the totalitarian trends of the New Deal,” asserted James W. Fifield Jr., an eloquent Congregationalist pastor from Los Angeles who, during the 1930s, created Spiritual Mobilization, a publicity offensive that joined megachurches like his with vocal, anti-liberal magnates like the Hollywood producer Cecil B. De Mille and J. Howard Pew Jr., the president of Sun Oil. They all believed religiosity, if widely and officially deployed, would be a mighty weapon in the battle against collectivist liberals at home and Communists abroad. As their ally, Billy Graham, preached in 1951 at one of his ever popular crusades, Americans urgently needed to rededicate themselves to “the rugged individualism that Christ brought” to the world.

But a funny thing happened on the road to spiritual and political redemption. By the mid-1950s, officeholders and social activists from every point on the ideological spectrum had signed on to the same righteous platform. In 1952, just before moving into the White House, Dwight ­Eisenhower (who was named after Dwight Moody, the renowned Gilded Age evangelist) told a gathering at the Waldorf Astoria: “Our form of government has no sense unless it is founded in a deeply felt religious faith, and I don’t care what it is.” Only a hardened atheist could object to such an ecumenical bromide. Under Eisenhower, Kruse writes, “the state no longer seemed ‘pagan,’ . . . and liberals could present themselves as acting in accord with God’s will too.” Two years later, when Congress agreed to add “one nation under God” to the Pledge, not even the American Civil Liberties Union objected. One lone Jewish representative from Brooklyn, Abraham Multer, did argue that putting God’s name on the currency would not stimulate “one single person to be more religious.” But even he didn’t dare vote against the bill.