what is the {start time} for {Mark Rothko} has {country of citizenship} as {United States of America} ?
When did Mark Rothko become a citizen of the United States?
SELECT ?value WHERE { wd:Q160149 p:P27 ?s . ?s ps:P27 wd:Q30 . ?s pq:P580 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q160149> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P27> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q30> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

What year did Mark Rothko become a US citizen?