Question: when did under god get added to pledge
[{'answer': 'In 1954', 'provenance': [{'wikipedia_id': '59581', 'title': 'Pledge of Allegiance', 'start_paragraph_id': 1, 'start_character': 589, 'end_paragraph_id': 1, 'end_character': 596, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]