Question: What site of the Battle of Vicksburg has an official symbol of a wooden duck?
Answer(s):
answer: Mississippi

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.01hf7f)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.01hf7f ns:time.event.locations ?x .
?x ns:government.governmental_jurisdiction.official_symbols ?c .
?c ns:location.location_symbol_relationship.symbol ns:m.01ldpz . 
}