In the early hours of May 6, 1856, the steamboat Effie Afton barreled into a pillar of the Rock Island Bridge--the first railroad bridge ever to span the Mississippi River. Soon after, the newly constructed vessel, crowded with passengers and livestock, erupted into flames and sank in the river below, taking much of the bridge with it. As lawyer and Lincoln scholar Brian McGinty dramatically reveals in Lincoln's Greatest Case, no one was...