Question: Who was Vice President to the person who said "Seriously,  I do not think I am fit for the Presidency."?
Answer(s):
answer: Hannibal Hamlin
answer: Andrew Johnson

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:people.person.quotations ns:m.048jc3k . 
?c ns:government.us_president.vice_president ?x .
}