Question: what does the blue square on the american flag mean
[{'answer': "the `` union ''"}, {'provenance': [{'wikipedia_id': '11447', 'title': 'Flag of the United States', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 813, 'bleu_score': 0.9727108480043881, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18073027903671413713}, 'section': 'Section::::Abstract.'}]}]