Question: Which Kennedy family member held his government position until 1953-01-03?
Answer(s):
answer: John F. Kennedy

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.01qlg1)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.01qlg1 ns:people.person.children ?x .
?x ns:government.politician.government_positions_held ?c .
?c ns:government.government_position_held.to "1953-01-03"^^xsd:dateTime . 
}