Question: when was hemp made illegal in the united states
[{'answer': '1937', 'provenance': [{'wikipedia_id': '11164587', 'title': 'Legal history of cannabis in the United States', 'start_paragraph_id': 1, 'start_character': 539, 'end_paragraph_id': 1, 'end_character': 543, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '11164587', 'title': 'Legal history of cannabis in the United States', 'start_paragraph_id': 35, 'start_character': 0, 'end_paragraph_id': 35, 'end_character': 1412, 'bleu_score': 0.991578759953019, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2414688761485274545}, 'section': 'Section::::Criminalization (1900s).:Marihuana Tax Act (1937).\n'}]}]