Question: In what location, with a currency of the U.S. Dollar, was the Battle of Vicksburg fought?
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:location.statistical_region.gdp_nominal ?c .
?c ns:measurement_unit.dated_money_value.currency ns:m.09nqf . 
}