Question: who was president when iowa became a state
[{'answer': 'President James K. Polk', 'provenance': [{'wikipedia_id': '26810748', 'title': 'Iowa', 'start_paragraph_id': 43, 'start_character': 152, 'end_paragraph_id': 43, 'end_character': 175, 'bleu_score': 1.0, 'section': 'Section::::History.:U.S. settlement and statehood, 1832–1860.\n'}]}, {'provenance': [{'wikipedia_id': '26810748', 'title': 'Iowa', 'start_paragraph_id': 43, 'start_character': 0, 'end_paragraph_id': 43, 'end_character': 529, 'bleu_score': 0.9766041382465441, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10497032374796009308}, 'section': 'Section::::History.:U.S. settlement and statehood, 1832–1860.\n'}]}]