To the question of whether the Civil War was inevitable, I have to answer with a qualified affirmative. I used to believe that slavery was merely a sub-issue of the overarching “states’ rights” issues that caused the Civil War, but my studies have convinced me that every single “states’ rights” issue in the antebellum period was directly or peripherally related to the question of slavery. Legitimate sectional economic and social differences were either caused by or seriously aggravated by the fact that African slaves provided the bulk of labor below the Mason-Dixon Line. The voluntary abolition of slavery earlier in the nation’s history—during the Constitutional Convention, immediately after the Revolution, or even earlier during the colonial period—would have eased most of the sectional differences that led to disunion. There were opportunities along the way to solve the problem, but they were consistently put off for future generations to attempt to solve.
Woodworth provided a brief but interesting overview of the development of slavery, from the beginnings of the practice in colonial Virginia, through the dangerous shoals of the Constitutional compromises, the Missouri Compromise, and the increasing sectional hostility of the 1840s and 1850s, to the election of that “Black Republican” president, Abraham Lincoln. The question of slavery could have been resolved during the Constitutional Convention, but delegates from northern states were sufficiently concerned that southern intransigence over slavery would have prevented ratification of the document. This very well may have been the case, but southern slaveholders gained much more than they surrendered with the compromises that allowed the ratification of the Constitution.
By conceding to southern demands about slavery, however, northerners allowed the South eventually to paint itself into a corner, and the lack of viable options split the union and led to war. Southerners, wholly dependent on slave labor and lacking a sufficient population of white laborers, could not allow emancipation without ruining them financially. Surrounded and outnumbered by a race they considered inferior, white southerners feared slave revolts even more than they worried about northern abolitionists. Faced with economic disaster and race war, southerners felt they had no choice but to hold on desperately to their “peculiar institution.” Their desperation was betrayed by the increasingly tortured logic and language they used to defend slavery, and the apologists resorted to Freehling’s absurdly oxymoronic “reasonable extremism.” In an atmosphere of such sectional hostility, with southerners convinced of northern abolitionist schemes and terrified of the consequences, disunion and war appears to have been a foregone conclusion.
Many knew what the consequences would be, long before they came to pass. In a letter to his daughter-in-law in 1820, John Adams wrote, “We must settle the question of slavery’s extension now, otherwise it will stamp our National Character and lay a Foundation for calamities, if not disunion.”
 Steven E. Woodworth, This Great Struggle: America’s Civil War (Lanham, MD: Rowman & Littlefield, 2011), 1-24.
 Joseph J. Ellis, Founding Brothers: The Revolutionary Generation (New York: Alfred A. Knopf, 2001), 88-96; John Ferling, A Leap in the Dark: The Struggle to Create the American Republic (New York: Oxford University Press, 2003), 284-290.
 William W. Freehling, The Road to Disunion, Volume II: Secessionists Triumphant, 1854-1862 (New York: Oxford University Press, 2007), 278-87, http://site.ebrary.com/lib/apus/docDetail.action?docID=10170126.
 quoted in Ellis, Founding Brothers, 240-41.