During the twenty-four years from 1821 to 1845, Wolff traveled extensively: in Africa, visiting Egypt and Abyssinia; in Asia, traversing Palestine, Syria, Persia, Bokhara, and India. He also visited the United States, on the journey thither preaching on the island of Saint Helena. He arrived in New York in August, 1837; and, after speaking in that city, he preached in Philadelphia and Baltimore, and finally proceeded to Washington. Here, he says, “on a motion brought forward by the ex-President, John Quincy Adams, in one of the houses of Congress, the House unanimously granted to me the use of the Congress Hall for a lecture, which I delivered on a Saturday, honored with the presence of all the members of Congress, and also of the bishop of Virginia, and of the clergy and citizens of Washington. The same honor was granted to me by the members of the government of New Jersey and Pennsylvania, in whose presence I delivered lectures on my researches in Asia, and also on the personal reign of Jesus Christ.”—Ibid., pages 398, 399.