I got a question for you: The Pledge of Allegiance of the United States is an expression of allegiance to the Flag of the United States and the republic of the United States of America. It was originally composed by Captain George Thatcher Balch, a Union Army Officer during the Civil War and later a teacher of patriotism in New York City schools. The form of the pledge used today was largely devised by Francis Bellamy in 1892, and formally adopted by Congress as the pledge in 1942. The official name of The Pledge of Allegiance was adopted in 1945. The most recent alteration of its wording came on Flag Day in 1954, when the words "under God" were added.

Based on this passage, when did they add one nation under god to the pledge of allegiance?
Let's think first:
The relevant sentence in the passage is: The most recent alteration of its wording came on Flag Day in 1954, when the words "under God" were added.
Therefore, the answer is 1954.