Question: what was the first major battle of the civil war to be fought on union soil
[{'answer': 'The Battle of Antietam', 'provenance': [{'wikipedia_id': '84849', 'title': 'Battle of Antietam', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 22, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '84849', 'title': 'Battle of Antietam', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 618, 'bleu_score': 0.9575690457118191, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11229961446295559570}, 'section': 'Section::::Abstract.'}]}]