Sure there is. It's in the acknowledgement of the title.
And this is detailed where?
The later correspondences are in the War of the Rebellion records. One of particular interest reads as follows:
"HONORABLE GENTLEMEN: Your colleague, Mr. Soutter, has handed me your letter of 11th November, with which, in conformity with the instructions of your Government, you have sent me a copy of the manifesto issued by the Congress of the Confederate States and approved by the most honorable President, in order that the attention of the government of the Holy See, to whom, as well as to the other Governments, you have addressed yourselves, might be called to it. The sentiments expressed in the manifesto tending, as they do, to the cessation of the most bloody war which still rages in your countries and the putting an end to the disasters which accompany it by proceeding to negotiations for peace, being entirely in accordance with the disposition and character of the august head of the Catholic Church, I did not hesitate a moment in bringing it to the notice of the Holy Father." - Letter of Cardinal Antonelli to A. Dudley Mann, confederate diplomat to the Vatican, December 2, 1864 (emphasis added)
Note in particular to the repeated references to the confederate government and its officials, as well as the characterization of the war as one between two COUNTRIES.
Nonsense. Justice Grier refers to it as a rebellion.
The later correspondences are in the War of the Rebellion records.
Acknowledgement of receipt of an unsolicited correspondence? And the reply from the Holy Father was? Or was there a reply at all? And what about this protection from arrest you spoke of?