Question: when did the poor people's campaign start
[{'answer': 'December 4 , 1967', 'provenance': [{'wikipedia_id': '3701061', 'title': "Poor People's Campaign", 'start_paragraph_id': 18, 'start_character': 35, 'end_paragraph_id': 18, 'end_character': 52, 'bleu_score': 1.0, 'section': 'Section::::Development.:Publicity.\n'}]}, {'provenance': [{'wikipedia_id': '3701061', 'title': "Poor People's Campaign", 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 605, 'bleu_score': 0.7505534412637761, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6291393043471751269}, 'section': 'Section::::Development.:Publicity.\n'}]}]