Question: when were passports required to enter the us
[{'answer': '1978', 'provenance': [{'wikipedia_id': '3104779', 'title': 'United States passport', 'start_paragraph_id': 11, 'start_character': 114, 'end_paragraph_id': 11, 'end_character': 118, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '3104779', 'title': 'United States passport', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 274, 'bleu_score': 0.9560167778278961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6689827413073142404}, 'section': 'Section::::History.\n'}]}]