John Wolff of Indiana.
John Wolff of Indiana was Minister of War in the Cabinet of Governor-General William Johnson. Wolff represented the Confederation of North America in the 1853 peace negotiations at The Hague to end the Rocky Mountain War. Wolff and his Mexican counterpart, Senator Frank Rinehart, agreed to reinstate the arbitration panel established in 1845, consisting of representatives from the Germanic Confederation, the Netherlands, and Spain.
Sobel does not say whether Wolff continued to serve as Minister of War in the Cabinet of Johnson's successor, Whitney Hawkins.
Sobel's source for John Wolff's career as Minister of War is Frank Taft's The End of the War: The Hague in 1853 - 1855 (Melbourne, 1967).