In the classic novel "Huckleberry Finn," Mark Twain depicts Huck and his slave companion Jim planning to flee to the Northern "free states" (see References 1); ironically, they end up drifting South down the Mississippi River with disastrous results. Although this concept of North-as-freedom versus South-as-slavery oversimplifies the differences in Northern and Southern politics in the antebellum era, most of the political splits that occurred before the Civil War centered on the idea that going north represented a newer economic freedom, while going south meant drifting back into the slavery of older times. The river divided the country both politically and geographically.

The Nullification Crisis

The most predominant difference between the two halves of the country was the North's increasingly industrial economy, while the South remained plantation-based and agrarian. The Tariff Act of 1828, which taxed Great Britain for American goods, brought these differences into the political arena, since the tariff decreased Britain's demand for raw cotton from the South, but benefited clothing manufacturers in the North. Vice President John C. Calhoun proposed a state's right to "nullify" a detrimental federal law, and South Carolina did so in 1832, foreshadowing the South's future secession from the Union.

Free Labor as Rallying Cry

Historian Eric Foner noted that the first Republican nominating convention, held in Philadelphia in 1856, advocated the expanse of "free labor ... the new party's rallying cry," and opposed any expansion of a slave-based economy, the force that kept southern plantations thriving. This gauntlet thrown down at the South's feet was one of the first clear demarcations of the differences in Northern and Southern politics, and it proved prophetic. Four years later, the Republican party successfully championed Abraham Lincoln, who as the 16th president issued the Emancipation Proclamation.

Right to Secession

Once it became obvious to Southern states that politico-economic unity was not possible in the Union, they called for states' rights, another precursor to their ultimate secession. South Carolina, at its 1860 Secession Convention, declared that the state had a constitutional right to secede from the Union. Historian Kenneth M. Stampp noted that the root of this belief lay in the Constitution's deliberately vague stance about the nature of statehood. Secessionists argued that the states, which created the Union, were therefore older than the Union and independent of economically damaging federal regulations.

Underground Railroad

Perhaps the most decisive political split between North and South was the Northern support of the Underground Railroad, an organized system that actively assisted slaves escaping from South to North and beyond to Canada. The schism between slaveholders and abolitionists can be traced back to George Washington's time. In fact, Washington once complained about one of his runaway slaves being helped by a "society of Quakers, organized for this purpose," according to PBS.org. The railroad was a symbolic reminder of Twain's political geography: North was freedom, while South was enslavement.