American scoundrel: the life of the notorious Civil War general Dan Sickles. Thomas Keneally. 2003.

Dan Sickles was a member of Congress, led a controversial charge at Gettysburg, and had an affair with the deposed Queen of Spain—among many other women. But the most startling of his many exploits was his murder of Philip Barton Key (son of Francis Scott Key), the lover of his long-suffering and neglected wife, Teresa. The affair, the crime, and the trial contained all the ingredients of melodrama needed to ensure that it was the scandal of the age. At the trial’s end, Sickles was acquitted and hardly chastened.