If you think Congress is a messy place now, you should’ve been there in the run-up to the Civil War. Yale history professor Joanne Freeman joins guest host John McCaa to talk about a time when pistols were routinely drawn and all-out brawls frequently erupted on the House floor. Her new book is called “The Field of Blood: Violence in Congress and the Road to Civil War” (Farrar, Straus and Giroux).