The question Americans asked in 1844 was, "Who the hell is James K. Polk?" Polk, of course, was not unknown, but was a highly unlikely presidential candidate given the availability of better-known options. Among the Democrats, this included Martin Van Buren, John C. Calhoun, and James Buchanan. Among the Whigs, Henry Clay was the clear frontrunner. Complicating the election were three other candidates: President John Tyler, a man without...