Question: who was the president of the union army
[{'answer': 'Abraham Lincoln', 'provenance': [{'wikipedia_id': '360126', 'title': 'Union Army', 'start_paragraph_id': 7, 'start_character': 128, 'end_paragraph_id': 7, 'end_character': 143, 'bleu_score': 1.0, 'section': 'Section::::Formation.\n'}]}]