Question: Who was the vice president under Lincoln, and ended his/her government position after February 25, 1857?
Answer(s):
answer: Andrew Johnson
answer: Hannibal Hamlin

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.0gzh)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.0gzh ns:government.us_president.vice_president ?x .
?x ns:government.politician.government_positions_held ?c .
?c ns:government.government_position_held.to ?num .
FILTER (?num > "1857-02-25"^^xsd:dateTime) . 
}