If you spend enough time with history trivia lovers, sooner or later somebody will hit you with the one about America’s “President for a Day.” They lean in with a grin, ask who was the 12th President, and when you say Zachary Taylor, they triumphantly declare, “Wrong! It was David Rice Atchison!” That’s when you’re supposed to look confused, and they get to explain that, for twenty-four hours in 1849, a little-known Missouri senator held the highest office in the land.