“Now he belongs to the ages,” Edwin Stanton is supposed to have said, when he learned of President Lincoln’s death. In a trivial sense at least, Stanton was obviously correct. We have Lincoln’s face on the five-dollar bill—a bill that used to be worth more than a Happy Meal, before Lincoln’s disciples degraded the currency—and his grandiose monument in Washington, with a grotesque statue by the Transcendentalist sculptor-politician Daniel Chester French. We even used to celebrate Lincoln’s birthday as a federal holiday, but, now that there is no god but the 14th Amendment and Martin Luther King, Jr., is its prophet, poor Lincoln’s stock has sunk so low that he is lumped together with Millard Fillmore, U.S. Grant, Warren Harding, and Jimmy Carter—those paragons of American political life—in a generic Presidents Day, whose very name suggests that Americans are determined to forget their past. Why not an “American Patriotic Holidays Day” or a “World Religions Day”? I shudder to make this joke, knowing that this is a country where all bad jokes come true. (Did you catch the inauguration ceremony on television?)
In a deeper sense, though, the Lincoln years and their legacy represent the most significant revolution that the United States have undergone. We went from being a confederation of republics that minded their own...