Question: when did public health start in the united states
[{'answer': '1798', 'provenance': [{'wikipedia_id': '224130', 'title': 'United States Public Health Service', 'start_paragraph_id': 2, 'start_character': 50, 'end_paragraph_id': 2, 'end_character': 54, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]