Not long after Columbus set sail for the New World, the French and Spanish brought slaves with them on various expeditions. Slaves accompanied Ponce de Leon to Florida in 1513, for instance. But a far greater proportion of slaves arrived in chains in crowded, sweltering cargo holds. The first dark-skinned slaves in what was to become British North America arrived in Virginia — perhaps stopping first in Spanish lands — in 1619 aboard a Dutch vessel. From 1500 to 1900, approximately 12 million Africans were forced from their homes to go westward, with about 10 million of them completing the journey. Yet very few ended up in the British colonies and young American republic. By 1808, when the trans-Atlantic slave trade to the U.S. officially ended, only about 6 percent of African slaves landing in the New World had come to North America.
Colonial slavery had a slow start, particularly in the North. The proportion there never got much above 5 percent of the total population. Scholars have speculated as to why, without coming to a definite conclusion. Some surmise that indentured servants were fundamentally better suited to the Northern climate, crops, and tasks at hand; some claim that anti-slavery sentiment provided the explanation. At the time of the American Revolution, fewer than 10 percent of the half million slaves in the thirteen colonies resided in the North, working primarily in agriculture. New York had the greatest number, with just over 20,000. New Jersey had close to 12,000 slaves. Vermont was the first Northern region to abolish slavery when it became an independent republic in 1777. Most of the original Northern colonies implemented a process of gradual emancipation in the late eighteenth and early nineteenth centuries, requiring the children of slave mothers to remain in servitude for a set period, typically 28 years. Other regions above the Mason-Dixon line ended slavery upon statehood early in the nineteenth century — Ohio in 1803 and Indiana in 1816, for instance.
To the point slavery was so bad because rebellion's triggered more rebels and they were fighting back for freedom some of them and other continued to work as slaves causing a little confusion in the slavery systems.
