The following was pasted on Facebook by a friend of mine who does very good research:

Just the Facts:
Before you attack anything in this post please understand that I did research at the Smithsonian Institute and the US Census Bureau. I also researched from several historical publications, Harvard university, Oxford university, the transatlantic slave trade database, slavevoyages-org, and a few others.
Information regarding the current slave trade came from the US Department of Defense, the US State Department, the united nations, amnesty international, and a confidential paper on Russian mining.
The historical African slave trade operated from the discovery of the New World until 1808 with a recorded exception being the slave ship “Clotilda” in 1860. There were more than 32,000 voyages that delivered more than 10 million captive slaves to the Americas.
Of the more than 10 million captive African slaves, less than 310,000 were brought to North America in what is now the USA and Canada. The vast majority went to South America and the Caribbean. More than 900,000 went to Jamaica. The first delivery of captive slaves in North America was in 1619 but slaves had been brought to the Caribbean for about 100 years before that time.
The largest slave importer in Jamaica was an ancestor of Senator Kamala Harris. Ms. Harris, contrary to her claims, does not have any verified American slaves in her ancestry. But she has at least five slaveowners in her ancestry.
Of all the Black people living in America who were born here, less than 6% can document their ancestry to people who were slaves in the United States. That is less than 1% of the current US population.
More than half of black Americans claiming to be descendants of slaves trace their slave history back to the Caribbean, including to Kamala Harris’s Jamaica.
In today’s world the countries exporting the most slaves are North Korea and China. North Korea sends about 20,000 people to Russia every year to work in the Russian mines. China sends about double that amount. Of all of the people sent every year to Russia from North Korea and China the only documentation I could find showed less than 10 people (eight) ever returned to China.