With the united states starkly divided and with many Americans asking what kind of nation we are, it seems a good moment to look back to November 1863 in Gettysburg, Pennsylvania, when Abraham Lincoln tried to answer the same question. Consecrating a Civil War battlefield where thousands of young men and boys had died four months before, he spoke of a nation “conceived in liberty, and dedicated to the proposition that all men are created equal.” For most Americans since, and for much of the world, those words have at­tained the status of scripture. We draw our sense of collective identity from them. They were, however, not strictly true, and Lincoln knew it.