Question: what was the anaconda plan in the civil war
[{'answer': 'cut the South in two', 'provenance': [{'wikipedia_id': '593326', 'title': 'Anaconda Plan', 'start_paragraph_id': 1, 'start_character': 319, 'end_paragraph_id': 1, 'end_character': 339, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'advance down the Mississippi River', 'provenance': [{'wikipedia_id': '593326', 'title': 'Anaconda Plan', 'start_paragraph_id': 1, 'start_character': 281, 'end_paragraph_id': 1, 'end_character': 315, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Union blockade of the Southern ports'}, {'provenance': [{'wikipedia_id': '593326', 'title': 'Anaconda Plan', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 636, 'bleu_score': 0.9678715417213161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11542246220193050155}, 'section': 'Section::::Abstract.'}]}]