Question: When did the former wife of Graf von Bismarck-Schönhausen donate a piece to the Smithsonian she purchased on her honeymoon with a different man?
Sentence (from "Kurt von Plettenberg"): Plettenberg belonged to the circle of close friends which included Claus Schenk Graf von Stauffenberg, Johannes Popitz, Ludwig Beck, Ulrich von Hassell, Carl-Hans Graf von Hardenberg and Fabian von Schlabrendorff.
Relevant evidence: No