Joel Barlow was the early Republic's most tenacious diplomat, a cheerful volunteer for difficult missions. His hard-won treaties with Algiers, Tunis, and Tripoli ended, at least briefly, the attacks of Barbary pirates on American shipping in the Mediterranean. And on the eve of the War of 1812, President Madison sent him to France, where he subsequently won important wartime concessions from Napoleon.Young Barlow wrote his epic poem The Vision...