22 Finally, We cannot pass over in silence those whose long-continued unhappy lot implores and demands succor from men of apostolic zeal; We refer to the Indians and the negroes who are to be found within the confines of America, the greatest portion of whom have not yet dispelled the darkness of superstition. How wide a field for cultivation! How great a multitude of human beings to be made partakers of the blessing derived through Jesus Christ!
Source: Longinqua (Vatican.va)