Spot on for what said - go read the links.
i did:
By SAM ROBERTSFEB. 21, 2005
That the latest movement of black Africans arriving voluntarily surpasses the total who disembarked in chains before the United States outlawed international slave trafficking is a bit of a statistical anomaly. That total, most historians now agree, was about 500,000, with an annual peak of perhaps 30,000, compared with the millions overall who were sold into slavery from Africa. Many died aboard ship. Most were transported to the Caribbean and Brazil, where they were vulnerable to indigenous diseases and to the rigors of raising sugar cane, which was harder to cultivate than cotton or rice, the predominant crops on plantations in the United States, where the slave population was better able to survive and reproduce.
The flow from Africa began in the 1970's, mostly with refugees from Ethiopia and Somalia, and escalated in the 1990's, when the number of black residents of the United States born in sub-Saharan Africa nearly tripled. Combined with the much larger flow of Caribbean blacks, the recent arrivals from Africa accounted for about 25 percent of black population growth in the United States over all during the decade. Nationally, the proportion of blacks who are foreign born rose to about 7.3 percent from 4.9 percent in the 1990's. In New York City, about 1 in 3 blacks are foreign born.
According to the census, the proportion of black people living in the United States who describe themselves as African-born, while still small, more than doubled in the 1990's, to 1.7 percent from about 0.8 percent, for a total estimated conservatively at more than 600,000. About 1.7 million United States residents identify their ancestry as sub-Saharan.
