Atlantic Slave Trade

Slavery was prevalent in Africa for centuries before the colonization of the New World. 

Many millions of Africans were enslaved after being captured in the widespread warfare between African states and ethnic groups. African tribal chiefs played a direct role in selling their captives to buyers for export to countries in Europe and Asia and many more to the Muslim world. Islam promoted history's largest slave system, including over a million Europeans and tens of millions of Africans.

Trans-Atlantic Slave Trade to the New World
 The slave trade began in the Spanish Americas around 1500 and in the U. S. about 1650.

 12.5 million Africans were shipped to the New World. 10.7 million survived the dreaded Middle Passage, disembarking in North America, the Caribbean and South America. 

Only 4% of the slaves came to the United States - 389,000 of the 10,700,000 sent to the New World

The vast majority of slaves, 96%, were sent to the Caribbean colonies, Central and South America. Malnutrition, poor housing, inadequate clothing, tropical disease, and overwork contributed to a high mortality rate and required large numbers of replacements. 

By the start of the Civil War in 1861, the total slave population in the United States had increased around 10 fold because of the birth rate. The original 450,000 increased to around 4,000,000. Had the Africans sent to the United States remained slaves in Africa or been sent to the Caribbean or South America, it is likely that many would not have survived to have descendants. 

The best data indicates that around 25% of the southern United States households owned slaves and that around 4,000 free Negroes owned around 20,000 slaves.  

In 1998, President Yoweri Museveni of Uganda called upon tribal chieftains to apologize for their involvement in the slave trade:  "African chiefs were the ones waging war on each other and capturing their own people and selling them. If anyone should apologize it should be the African chiefs. We still have those traitors here even today." 

Acts Prohibiting the Importation of New Slaves began 60 years before the Civil War. 

The Slave Trade Act of 1794 passed by the United States Congress limited American involvement in the international slave trade. It was signed into law by President George Washington.

The Slave Trade Act of 1800  built upon the Slave Trade Act of 1794. It was signed into law by President John Adams.

The 1807 law Prohibiting Importation of Slaves to the United States was signed into law by President Thomas Jefferson. Jefferson had promoted the idea since the 1770s and called for its enactment in his 1806 State of the Union Address.

In 1819 Congress passed yet another act that authorized the president to send "armed vessels of the United States, to be employed to cruise on any of the coasts of the United States ... or the coast of Africa" to interdict slave traders. The act authorized the president to appoint agents to receive rescued Africans and return them to the continent of their birth.

https://en.wikipedia.org/wiki/Slave_Trade_Act_of_1794
https://en.wikipedia.org/wiki/Slave_Trade_Act_of_1800
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President Lincoln issued the final Emancipation Proclamation on January 1, 1863. The Proclamation freed only the slaves in the states in rebellion against the Federal government. It did not free the slaves held in Union states. At the end of the Civil War on December 6, 1865 the US Congress passed the 13th Amendment to the Constitution which abolished slavery through the United States. 

Approximately 620,000 soldiers died from combat, accident, starvation, and disease during the Civil War. Total military deaths for World War I and World War II were around 520,000.