Question: who served as president of the confederate states of america
[{'answer': 'Jefferson Davis', 'provenance': [{'wikipedia_id': '636208', 'title': 'President of the Confederate States of America', 'start_paragraph_id': 3, 'start_character': 224, 'end_paragraph_id': 3, 'end_character': 239, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '636208', 'title': 'President of the Confederate States of America', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 455, 'bleu_score': 0.9028586696953821, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14623658880332892705}, 'section': 'Section::::Abstract.'}]}]