 In the United States the slave population was largely able to maintain its numbers, and even many slave-owners accepted the evils of the African slave-trade and the need to abolish it.Pius wrote letters to the restored King of France in 1814 and the King of Portugal in 1823 urging the same thing.By now the Papacy was under political pressure from the British government, as British support was needed at the Congress of Vienna for the restoration of the Papal States.