Question: when did the states of america become united
[{'answer': '1776', 'provenance': [{'wikipedia_id': '63876', 'title': 'History of the United States', 'start_paragraph_id': 2, 'start_character': 33, 'end_paragraph_id': 2, 'end_character': 37, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '63876', 'title': 'History of the United States', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 975, 'bleu_score': 0.921236315083064, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6198446208920019942}, 'section': 'Section::::Abstract.'}]}]