Neo, that would depend upon when and where you viewed slavery in the history of the United States. I'll try to be as brief as possible, while touching upon crucially important descriptions.
Slave originally arrived in what would become the United States when a Dutch ship was driven north of the Windward Islands by a storm. The captain knew that the Spanish had once had colonies along that coast, and in looking for a haven, as his slaves died at an alarming rate, he found Jamestown. There he managed to sell a few, but people were largely not interested, so he decided to cut his losses, and left the rest of the ill and injured there, taking a handful of healthy people south with him to sell in the Windward Islands.
The islands of the Carribean were soon dedicated to a monoculture in sugar. Because of the nature of the work, Europeans did not do well, and often did not survive in that climate. The ability to run sugar plantations with white indentured workers was limited, and the ability to find those willing to make the effort declining rapidly. The Dutch and the English therefore brought in west African negroes. Without anyone understanding the process, these people survived better than anyone else. The west African negro and the Koreans both have a propensity for sickle cell anemia. The quaternary stage of the life-cycle of the malarial plasmodium is a colonization of the red blood cells. Therefore, west African negroes has a built-in resistance to death from malaria, and were generally not as weakened by the disease as were whites who survived it. None of this was known in any scientific sense at the time, but it was understood that these slaves did better than any other laborers.
In Virginia, there was a monoculture in tobacco. Initially, slavery was not attractive as there were no actual plantations, and the tobacco cultivators were small holders working limited plots. A man and his sons could usually supply all the labor without the expense of feeding, clothing and housing slaves. Slavery was therefore very slow to take root in the colonial south. There was even less need of it in New England. The same was true in the Maryland colony. Delaware, originally a Swedish colony, was taken over by the Dutch. Dutch colonial patterns were radically different from English and French patterns. The Dutch tended to encourage immigration through the grant of large estates to individuals who would then privately recruit tenants. When a tobacco monoculture took root in Delaware, the Dutch, with an already large investment in the slave trade, quickly supplied their labor with slaves. Slavery was in place and growing in Delaware when the English took over New Amsterdam from the Dutch, from which the colonies of New York, New Jersey and Delaware were created.
The colonies of the Carolinas were not created until after the restoration of the monarchy in England in 1660. Charles Stuart was indebted to many people for the support for the restoration. First and foremost, he was indebted to George Monck, whose march south from Coldstream in Scotland with the Parliamentary Guard had lead to his restoration. To Monck and other of his closest associates, such as Prince Rupert of Bohemia and John Churchill (who would one day become the first Duke of Marlborough), he granted a charter for the Company of Gentlemen Adventurers Trading into Hudson's Bay. His next largest debt was to an English Admiral, Charles Penn, who had supported his father before that king was executed, and had latterly advanced Charles and James Stuart a loan of 16,000 pounds sterling at the time of the restoration. Penn had died, however, before Charles ascended the throne, so a large grant was made to his son, William Penn, who had become a member of the Society of Friends, dubbed the Quakers by Lord Justice Jeffreys. Penn could not outlaw slavery, but he could and did prohibit the trade in his colony, and his policy of religious toleration lead to the colony filling up with, in addition to Quakers, Scots-Irish Presbyterians and German charismatics, who became small-holding farmers with little use for slaves and no interest in slavery as an institution.
In Virginia, slavery had been slowly and fitfully growing. The tobacco monoculture quickly exhausted the soil, and it was necessary to acquire and clear more land to continue its production (a very lucrative business), so slaves were becoming more attractive as small-holders translated themselves into plantation owners. Charles repaid his debt to Lord Fairfax with a huge grant of lands in the territory already allocated to the Commonwealth of Virginia, and this was sold off in large tracts which made slavery attractive to plantation owners. The existing tobacco growers had to expand their holdings and their slave labor to compete. Small holders unable to compete or unwilling to use slavery moved in to marginal lands in Virginia or into what would become North Carolina.
Charles repaid the debt to the bulk of the remaining creditors with the grants which became North and South Carolina. Although the tobacco monoculture was introduced into North Carolina, the tradition of small holding was already established there, and much of the immigration was Scots-Irish Presbyterians and French Huguenots, who once again as in Pennsylvania, had little use for slaves and no interest in slavery. Large plantations were much less common there than they were becoming in Virginia and Maryland.
South Carolina became a unique society, however. There were two large monocultures which took off with a vengeance. These were the production of rice which was sold to slave owners in the Windward islands to feed their slaves, and the production of indigo. The owners of large tracts of land usually did not live on their property, but instead left the management of their land and slaves to overseers, while living in conspicuous luxury in Charles Town (modern Charleston).
When Oglethorpe established a penal colony in what would become Georgia, the equation of a lot of slaves clearing a lot of land in short order, to exploit it to exhaustion and then move on was well-established. Georgia filled up quickly with people eager to exploit that system.
By the time of the French and Indian War, many Virginians long established on the land were becoming disenchanted with the entire system of the continual exploitation of new land, but were heavily indebted to the vested interests in London who robbed them shamelessly. Washington returned to the estate he had inherited from his half-brother Lawrence, and quickly realized that slavery was useless in any other context than the relentless exploitation and exhaustion of new land. Although holding large tracts of western lands acquired when he was a surveyor before the war, he abandoned the tobacco monoculture, knuckled down to pay off the estates debts to London factors, and began to diversify his agronomy. Some Virginia and Maryland planters followed his lead; many others who were dedicated to the by then established system of the monoculture became alarmed at the prospect of Washington educating and manumitting his slaves (he had about 300 hundred from Lawrence's legacy, and another 300 from his marriage to Martha Dandridge Custis). Both colonies quickly passed laws outlawing the education of slaves, and holding that the children of slaves remained slaves even if the parents had been manumitted. The Washington estate finally ended by paying pensions to the slaves until after 1830, more than a generation after Washington's death.
In the inland hill country of the Carolinas and Georgia, the tobacco monoculture had been established, but was quickly running out of new land to exploit. After the Revolution, the western regions of these states as well as of Virginia and Maryland filled up with small holders, and slavery was not a significant institution in those regions. (This accounts for why the western counties of Virginia seceded from the state in 1861, and were admitted to the Union as the state of West Virginia in 1863; the eastern portion of Tennessee had been filled up with small holders from Virginia and North Carolina, and it, too, remained a Union stronghold during the American civil war.)
Looking around for a more profitable monoculture, the plantation owners in the hill country of the Carolinas and Georgia came up with cotton, but it was not initially very profitable because it was labor intensive. The invention of the cotton gin, however, made rapid, large production possible. With the successful conclusion of the Creek War in 1813, the territory which would become Alabama and Mississippi was opened to settlement, and aspiring and avaricious members of the middle class of the coastal states took the opportunity to acquire large tracts of land at low prices, and exploit the cotton monoculture exactly as had been done with the tobacco monoculture. The worst of the abuses of slavery took place in this environment. Unlike the old plantations of the coastal South, in which generations of plantation families had long lived closely with generations of slaves, the new cotton monoculture exploiters cared not one whit for the means by which slaves were acquired, nor how they were maintained. In far too many cases, they were literally worked to death. Cotton became "King," to feed the insatiable maws of European mills.
Nouveau arriviste families, such as that which produced Jefferson Davis, moved into Alabama and Mississippi to exploit the cotton monoculture, and seemingly overnight became wealthy, sent their sons to college, and adopted all the trappings of the dollar aristocracy which reigned supreme throughout the United States. From an embarrassing but useful "peculiar" institution, slavery became a symbol of middle class status, and families which might have as easily employed white domestics now bought slaves to be housemaids and stable boys.
The political equation was even more pernicious. Pinckney and Ruffin during the constitutional convention had quickly realized that their electorate was limited because of the greater proportion of non-franchised blacks in their population, and that they would therefore be easily overwhelmed in the House of Representatives. Therefore, the "Three-fifths" compromise was hammered out, by which each five slaves were considered to represent the equivalent of three members of the white population, giving Southern states far more representatives for the proportion of their white, voting population than in the north, although a larger population in absolute terms per representative. This gave the South inordinate political power. An informal compromise agreement was worked out to prevent Southern obstructionism in Congress whereby the admission of a "free" state could only pass the Congress in tandem with the admission of a "slave" state.
But by the time of the Mexican War--justifiably seen in the North as "Mr. Polk's War" to expand slave state territory--the equation no longer worked. West of the Mississippi, the only reliable monoculture north and west of Louisiana and Arkansas was grain growing, because of the more arid character of the country and climate. Grain monoculture not only did not need slavery, with the agronomic methods and technology of that era, it worked better with small holders. Even the accession of new slave states did not have the effect of creating a competetive political power for slaver owners. The power of the three-fifths compromise to support the political agendae of slave owners was rapidly waning.
This is why, when the idiotic split which Southerners created in the 1860 election in the Democratic party lead to the election of a minority president, Lincoln, Southerners reacted rashly, nearly in an hysterical manner. No plans were being made by the Republicans to attempt to abolish slavery. Savvy political observers could see that the political power of the South was eroding due to the nature of the populating of new territory, and the heavy influx of European immigrants, especially after the failed Socialist uprisings in 1848 in Europe.
Southern politicians could see this as well. They used the claim that the Republicans would end slavery as a propaganda tool, and an effective one because the Republicans has exploited the abolitionists to gain the electoral clout needed to make a decent showing in the 1860 elections. Had the South not split the Democratic ticket between Douglas and Breckenridge, the Democrats would have buried the Republicans. Even with the election of Lincoln, Republicans were a minority in Congress. But Southerners over-reacted, and James Chestnut lead the South Carolina delegation out of the Congress, while the state convention voted for secession. Even at this late and extreme juncture, the South might have succeeded in secession if they had not been overcome with a fit of hubris which would destroy them in less than five years. Lincoln needed a causus belli to call for the state militias, and Southerners presented it by seizing or attempting to seize federal property. At Charleston, this was accomplished by arresting federal customs agents and marshalls, and summoning Fort Sumter. The spineless hand-wringing of the lame duck Buchanan administration only encouraged such efforts. At Pensacola, an alert and active lieutenant of the Artillery moved quickly to destroy military supplies, spike gun tubes he could not throw in the bay or carry off, and occupy the harbor defenses. The south definitely lost on that account. Virginia then seceeded, and stupid inaction on the part of federal officials allowed the seizure of the arsenal at Harpers Ferry with almost all of its gunsmith machinery intact. The attempt of Confederate sympathizers to seize the arsenal at St. Louis was foiled by Franz Sigel, one of the German "Forty-eighters" who had come to this country, with staunch Socialist German small holders who had settled in Missouri and southern Illinois after fleeing Europe.
The war only happened when it did because of a hothead attitude in the South, actively fostered by Southern politicians who saw the handwriting on the wall, and thought to move quickly enough to prevent the inevitable collapse of the "peculiar institution." They were about twenty years too late--their way of life was already doomed, and their actions simply brought upon the nation more than four years of horrible strife and misery, and the deaths of a million Americans.
Throughout, chrisitians figured prominently as supporters of slavery, and far less prominently as opponents of slavery. Which is why this has become a part of this discussion. Haven't been very brief, have i?
