Mediation to Avoid War
Rudolf Schleiden, Hanseatic States representative at Washington in 1861, was earnestly interested in averting war between North and South and offered to mediate the crisis.  He had approached Lincoln even before his inauguration to authorize peaceful negotiation with the South to avoid bloodshed, but to no avail.
Bernhard Thuersam, Chairman
North Carolina War Between the States Sesquicentennial Commission
"Unsurpassed Valor, Courage and Devotion to Liberty"
"The Official Website of the North Carolina WBTS Sesquicentennial"
Mediation to Avoid War
“To avert civil war and the consequent disruption of trade seemed to Schleiden a foremost duty. He became then, an earnest advocate of mediation. . . and offered his services to [Secretary of State William] Seward in the hope that he alone might be able to negotiate an armistice which would maintain a peaceful status until Congress could assemble. [Lincoln told him that] “he did not have in mind any aggression against the Southern States, but merely the safety of the Government in the capital and the possibility to govern everywhere.”
On the evening of April 24 Schleiden departed secretly for Richmond . . . [and immediately wrote] to Vice President [Alexander H.] Stephens asking for an interview, to which the latter replied that he would be happy to see him immediately. “The actions of Seward and Lincoln had filled the South with suspicion,” Stephens said, “but neither the Government at Montgomery not the authorities of Virginia contemplated an attack on Washington.”
He added . . . “Public opinion was embittered against the United States because of the strengthening of Forts Pickens and Fort Monroe, and the destruction of the arsenal at Harper’s Ferry, and navy yard at Norfolk.” In view of these facts Stephens favored a “de facto truce through tactful avoidance of an attack by both sides,” rather than a formal armistice.
In a formal letter, written after the conference, Schleiden asked for a frank statement of the terms which the South would be ready to grant and accept for the purpose of securing the maintenance of peace and gaining time for reflection.  “I believe that your complying with my above request,” wrote Schleiden, “offers the last prospect for attaining a peaceful solution of the present crisis.”
To this letter Stephens replied, stating that the Government of the Confederacy had resorted to every honorable means to avoid war, and that if the United States had any desire to adjust amicably the questions at issue it should indicate its willingness by some authoritative way to the South.
However, he added, referring to the United States, “it seems their policy to wage war for the recapture of former possessions looking to the ultimate coercion and subjugation of the people of the Confederate States to their power and domain.  With such an object on their part persevered in, no power on earth can arrest or prevent a most bloody conflict.”
After the last conference with Stephens, Schleiden returned to Washington, reaching the Capital on the afternoon of the 27th.  Immediately upon his arrival he addressed a letter to President Lincoln, inclosing is correspondence with Stephens. After stating that the Southern States were arming in self defense, he reported that if the South were assured the President would recommend to Congress when it assembles on July 4 a speedy and amicable adjustment of the differences and the propriety of treating with commissioners of the Southern States, there would be not any danger of a conflict.
At the request of the President, Seward replied to this letter in an informal and unofficial communication from the Department of State.  Seward informed Schleiden that Lincoln was of the opinion that a continuance of the negotiations would be without beneficial result.
In view of this fact, Schleiden wrote to Stephen’s:  “It is only now and with deep regret that I can inform you that my attempt at contributing toward gaining time for reflection and if possible a favorable adjustment of the existing differences has failed.”
Finally, on May 2, 1861, Schleiden wrote to his Government: “I regret to report to the honorable Senate committee that my attempts to mediate a truce and thereby furnish the opposing parties time for quiet reflection has not been successful.”
Schleiden [later] reported in a dispatch that Lincoln had said to Judge Thomas of Massachusetts in mid-1864 that he would be satisfied if his successor, as he was despondent of his reelection chances, was elected from the Republican party. If that was not the case, he feared he would spend the rest of his life in jail for repeated violations of the Constitution.”
(Rudolf Schleiden and the Visit to Richmond, April 25, 1861, Ralph Haswell Lutz,  Annual Report of the American Historical Association for 1915,  Smithsonian Institution, 1917, pp. 210-216)