Question: when was the first thanksgiving celebrated in the united states
[{'answer': 'October 1621', 'provenance': [{'wikipedia_id': '8304348', 'title': 'Thanksgiving (United States)', 'start_paragraph_id': 2, 'start_character': 141, 'end_paragraph_id': 2, 'end_character': 153, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '8304348', 'title': 'Thanksgiving (United States)', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 458, 'bleu_score': 0.9257921357402691, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15999697239210997099}, 'section': 'Section::::Abstract.'}]}]