Question: who led army troops against protesters in washington d.c. during the summer of 1932
[{'answer': 'Walter W. Waters', 'provenance': [{'wikipedia_id': '399959', 'title': 'Bonus Army', 'start_paragraph_id': 1, 'start_character': 456, 'end_paragraph_id': 1, 'end_character': 472, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '399959', 'title': 'Bonus Army', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 491, 'bleu_score': 0.778966550698942, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14156133651706758439}, 'section': 'Section::::Abstract.'}]}]