Any serious historical review of the war’s cause in early 1861 cannot overlook President James Buchanan’s realization, undergirded by his Attorney General Jeremiah Black, that to wage war against a State was the very definition of treason against the United States (Article III, Section 3). Lincoln would not be constrained by this.
Secessionist Abolitionists
“From the 1830s on, abolitionists argued for the secession of the North from the Union and the American Anti-Slavery Society passed the following resolution:
“That the Abolitionists of this country should make it one of the primary objects of this agitation to dissolve the American Union.”
This was also the view of the Douglass Monthly, printed by Frederick Douglass. Fellow abolitionist Horace Greeley, editor of the New York Tribune wrote on February 23, 1861, the day after Jefferson Davis was inaugurated President of the Confederate States of America:
“We have repeatedly said . . . that the great principle embodied by Thomas Jefferson in the Declaration of Independence, that governments derive their powers from the consent of the people, is sound and just; and that, if the Cotton States or the Gulf States, choose to form an independent nation, they have a clear moral right to do so. Whenever it shall be clear that the great body of Southern people have become conclusively alienated from the Union, and anxious to escape from it, we will do our best to forward their views.”
(Was Davis a Traitor, or Was Secession a Constitutional Right Previous to the War of 1861, Albert Taylor Bledsoe, Fletcher & Fletcher, 1995 (original 1866), p. 149)