Perhaps the best-known example of a secession taking place within the borders of a formerly unified nation was the withdrawal (1860–61) of the 11 Southern states from the United States to form the Confederacy. This action, which led to the Civil War, brought to a head a constitutional question that had been an issue in the United States since the formation of the union. It was the principal point in the controversy over states' rights.
The secessionists argued that the union created by the Constitution was only a compact of sovereign states and that power given to the federal government was only partial and limited, not paramount over the states, and effective only in the specific fields assigned it. The states, being sovereign, had the legal right to withdraw from the voluntary union. The opponents of the right of secession believed that the Constitution created a sovereign and inviolable union and that withdrawal from that union was impossible. Prior to the Civil War secessionist sentiments were evidenced in both the North (see Hartford Convention) and South, but as the North grew more powerful, talk of secession became more common in the South.
The nullification movement, which held that any state could declare null and void any federal law that infringed upon its rights, was an attempt to eradicate the need for secession by giving the states complete sovereignty. Measures such as the Missouri Compromise and the Compromise of 1850 were merely delays in resolving whether the states or the federal government was to possess sovereignty. Desiring to maintain the slave system and threatened by the North socially and economically, the South finally seceded from the Union soon after the election of Abraham Lincoln. The defeat of the Confederacy in the bloody war that followed settled the constitutional controversy permanently.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.