Question: when did massachusetts become a part of the united states
[{'answer': 'February 6 , 1788', 'provenance': [{'wikipedia_id': '1645518', 'title': 'Massachusetts', 'start_paragraph_id': 22, 'start_character': 349, 'end_paragraph_id': 22, 'end_character': 366, 'bleu_score': 1.0, 'section': 'Section::::History.:Federal period.\n'}]}, {'provenance': [{'wikipedia_id': '1645518', 'title': 'Massachusetts', 'start_paragraph_id': 22, 'start_character': 0, 'end_paragraph_id': 22, 'end_character': 444, 'bleu_score': 0.970795021215021, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14446594230835615829}, 'section': 'Section::::History.:Federal period.\n'}]}]