Question: when was a people's history of the united states written
[{'answer': '1980', 'provenance': [{'wikipedia_id': '38802735', 'title': "A People's History of the United States", 'start_paragraph_id': 1, 'start_character': 40, 'end_paragraph_id': 1, 'end_character': 44, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]