Original: The date was chosen because the ship Restauration coming from Stavanger, Norway, arrived in New York Harbor on October 9, 1825 at the start of the first organized immigration from Norway to the United States.
Simplified: The date was chosen because the ship Restauration coming from Stavanger, Norway, arrived in New York Harbor on October 9, 1825. This was the start of the first organized immigration from Norway to the United States.