Question: when were federal troops removed from the south
[{'answer': '1877', 'provenance': [{'wikipedia_id': '463052', 'title': 'Compromise of 1877', 'start_paragraph_id': 0, 'start_character': 14, 'end_paragraph_id': 0, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '463052', 'title': 'Compromise of 1877', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1123, 'bleu_score': 0.987987443031558, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 602818476734061119}, 'section': 'Section::::Abstract.'}]}]