Slavery grounded southern society and culture, differentiating the South from the North, to which it remained intimately linked. It had not always been thus. Although northern and southern settlement had been fed by slightly different currents – the one more Puritan, the other more Cavalier – both derived disproportionately from British stock and both included a large component of yeoman farm families. Slaveholding, like indentured servitude, was taken for granted by all. Only gradually did the two regions diverge, as slavery advanced in the South and receded in the North.

During the early years of the Republic, most Southerners lived comfortably with a kind of layered citizenship: citizens of the new United States but deeply rooted in their discrete states, which they were wont to call “my country,” and in their local communities and households. Many Northerners of the day did the same, but fault lines appeared in the early Republic. By the Missouri crisis of 1819–20, the growing regional divergence in interests and values was clear to those who cared to notice. Today, many academics slight the significance – or deny the existence – of southern distinctiveness, arguing that Southerners were Northerners by another name even during the first half of the nineteenth century: aspiring capitalists, cultivators of conventional middle-class mores, and racists.