Three history professors spent a recent Sunday afternoon leaning into microphones in a small studio near the University of Virginia, trying to become radio stars — and attempting to invent a new model of educational programming in the process. When they don their bulky headphones, they become "the American history guys," hosts of the monthly public-radio show BackStory. Peter S. Onuf, a UVa history professor known for his work on the American Revolution, gives his perspectives on the 18th century. Edward L. Ayers, president of the University of Richmond and a Civil War historia...