I have deemed it important to trace out some of the leading events which have transpired under the pontificates of Gregory XVI, Pius IX, and Leo XIII, up to the present time. In this way only is it possible to understand the full meaning of the revolution which led to Italian unity and the overthrow of the temporal power of the pope by Roman Catholic populations, and what is involved in the demand for its restoration. In doing this I have considered only such matters as are _politico-religious_, in the sense common among the people of the United States, and which can not be made a part of religious faith without doing violence to the recognized spirit of our civil institutions. Thus I have avoided any conflict with those who prefer the Roman Catholic to the Protestant form of religious belief, for the express reason that I have neither the purpose nor desire to question their right to do so. It seems to me that the constitutional guarantee which protects this right ought to be satisfactory to all, and can not be disturbed without imperiling our Government. Therefore, all I desire will be accomplished if I shall succeed in convincing thoughtful Roman Catholics that it will be far better for all of us if they shall decline to accept the _politico-religious_ teachings of the Jesuits as a part of their religious faith, and content themselves without interference with the political affairs of their Christian brethren in Italy. They may maintain fidelity to the Government as patriotically as professed Protestants, without abating their devotion to the spiritual doctrines which prevailed in their Church before the fall of the Roman Empire enabled the popes to place the crown of temporal royalty upon their heads. To this end I would, if permitted, appeal to that portion of our population in all sincerity, and invoke the exercise of their intelligence no less than their patriotism. And if any of them shall peruse this volume, and carefully consider its contents, they will see that what I have written centers in the hope that the Protestants and Roman Catholics of the United States shall live together in the concord of Christian fellowship, emulating each other in those things that shall tend most to promote their mutual happiness, and preserve for their common posterity the civil and religious liberty guaranteed by our Constitution and laws.