Question: who built the first railroad in the united states
[{'answer': '1795', 'provenance': [{'wikipedia_id': '254044', 'title': 'Timeline of United States railway history', 'start_paragraph_id': 2, 'start_character': 11, 'end_paragraph_id': 2, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '254044', 'title': 'Timeline of United States railway history', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 621, 'bleu_score': 0.9804854598160591, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1417980844099678403}, 'section': 'Section::::1795-1829.\n'}]}]