Question: when was the american federation of labor founded
[{'answer': 'in December 1886', 'provenance': [{'wikipedia_id': '350020', 'title': 'American Federation of Labor', 'start_paragraph_id': 1, 'start_character': 129, 'end_paragraph_id': 1, 'end_character': 145, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '350020', 'title': 'American Federation of Labor', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 948, 'bleu_score': 0.9312522757207111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5596381803327337881}, 'section': 'Section::::Abstract.'}]}]