Due to illness he declined, but sent a letter appealing to the people of Alabama to remain in the Union, and give the North time to repeal laws against southern interests and to find common ground.[153]

Civil War
After efforts to prevent the Civil War ended with the firing on Fort Sumter, Northern Democrats, including Douglas, endorsed Lincoln's plan to bring the Southern states back into the fold by force. Pierce wanted to avoid war at all costs, and wrote to Van Buren, proposing an assembly of former U.S. presidents to resolve the issue, but this suggestion was not acted on. "I will never justify, sustain or in any way or to any extent uphold this cruel, heartless, aimless, unnecessary war," Pierce wrote to his wife.[153] Pierce publicly opposed President Lincoln's order suspending the writ of habeas corpus, arguing that even in a time of war, the country should not abandon its protection of civil liberties. This stand won him admirers with the emerging Northern Peace Democrats, but others saw the stand as further evidence of Pierce's southern bias.[154]
In September 1861, Pierce traveled to Michigan, visiting his former Interior Secretary, McClelland, former senator Cass, and others. 