Question: when did memorial day become a holiday honoring the american dead from all wars
[{'answer': 'By the 20th century', 'provenance': [{'wikipedia_id': '56191', 'title': 'Memorial Day', 'start_paragraph_id': 39, 'start_character': 0, 'end_paragraph_id': 39, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Decoration Day to Memorial Day.\n'}]}]