Initially, Mosby spoke out against secession, but he joined the Confederate army when the Civil War began. After the war, Mosby worked with the U.S. government, serving as the American consul to Hong Kong and in the U.S. Department of Justice.
Wikipedia contributors, "John S. Mosby," Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=John_S._Mosby&oldid=848111789 (accessed June 30, 2018).