Republican leaders bent upon pushing the South to war effectively scuttled the Crittenden compromise plan as they feared a national referendum would welcome peaceful compromise. Before and throughout the war, efforts to avoid and end the bloodshed came almost entirely from the South.
Bernhard Thuersam, Chairman
North Carolina War Between the States Sesquicentennial Commission
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The Core of the Anti-Republican Argument
"Thurlow Weed had been predicting since November  that if the Republicans could make the Union rather than slavery the central issue of the [sectional] crisis, a united North would rally behind him. He . . . did not hesitate to urge Lincoln to take advantage of the sudden outburst of patriotic fervor. From New York he told the president-elect, "We shall have a United north – a condition about which I have been filled with solicitude."
[But] the imminence of war stirred a desperation for peace . . . and conciliationist leaders launched another offensive, spearheaded once more by Senators Crittenden and [Stephen] Douglas. Despite Republican opposition . . . the encouragement they had had been receiving across the North and Upper South convinced them that Northern public sentiment was behind compromise, particularly the Crittenden plan.
With that support in mind, the two senators issued a joint letter assuring concerned Southerners that their rights could be secured in the Union. On January 3, citing numerous reports of massive public sympathy for a peaceful resolution to the crisis, Crittenden asked the Senate to refer his amendments to the people, to be decided upon in national convention. He also sought to attract Republican support by adding two propositions drawn from Douglas's failed proposal: a national ban on black voting and officeholding, and federal subsidization of black colonization to Africa.
[Douglas] charged the [uncompromising] Republicans with "attempt[ing] to manufacture partisan capital out of a question involving the peace and safety of the country." Worse, they refused to help resolve the horrific crisis even though it was their own actions that had caused it . . . [and attacked them] for being naïve ideologues: for all their talk of upholding the Constitution and enforcing the laws, he stormed, they had to deal with the basic fact that "the revolution is complete."
"In my opinion South Carolina has no right to secede," he declared, "but she has done it." The question now was not how to prevent disunion but how to reverse it – by force of arms or by a peaceful resolution of sectional differences? Here Douglas reached the core of the anti-Republican argument.
"Are we prepared in our hearts for war with our own brethren and kindred?" he demanded. "I confess I am not . . . I will not meditate war, nor tolerate the idea, until every effort at peaceful adjustment has been exhausted . . . I am for peace to save the Union."
(Lincoln and the Decision for War, the Northern Response to Secession, Russell McClintock, UNC Press, 2008, pp. 111; 115)