Justus Scheibert
Justus Scheibert (1831–1903) was an army captain, sent by Prussia to America to observe the American Civil War in order to learn the lessons to be learned and return to Prussia to teach these lessons to the Prussian troops. His writings became a source of Prussian, and later German, military strategy through five subsequent wars.
Series by Justus Scheibert: Seeing the Elephant