War, slave raiding, kidnapping, and politico-religious struggle accounted for the vast majority of Africans deported to the Americas. Several important wars resulted in massive enslavement, including the export of prisoners across the Atlantic, the ransoming of others, and the use of enslavement within Africa itself.

Ethnicity in the Modern Atlantic World , Chapter 9 from The Rise of African Slavery In The Americas by David Eltis

The Akan wars of the late seventeenth century and the first half of the eighteenth century were a struggle for power among states in the Gold Coast hinterland. Akwamu, Akyem, Denkyira, Fante, and Asante groups battled for more than half a century for control of the region. By the mid-eighteenth century, Asante emerged as the dominant force.

By 1650, Oyo had become a consolidated imperial power in the interior of the Bight of Benin by defeating the Bariba and Nupe in the north and other Yoruba states to the south. The wars between various Gbe groups resulted in the rise of Dahomey and its victory over Allada in 1724. The winners occupied the port of Whydah three years later but were then forced to pay tribute to the more powerful Oyo. These wars accounted for the deportation of over a million Africans along the Bight of Benin coast.

Biography of Mahommah G. Baquaqua, a Native of Zoogoo by Baquaqua, Mahommah Gardo and Moore, Samuel, fl. 1854

The sixty-year period of the Kongo civil wars, ending in 1740, was responsible for the capture and enslavement of many. Among them were the followers of the Catholic martyr Beatrice of Kongo, who tried to end the wars through pacifist protest.

Narrative of the Enslavement of Ottobah Cugoano by Cugoano, Ottobah

The spread of militant Islam across West Africa began in Senegambia during the late seventeenth century. The jihad led to two major political transformations: the emergence in the late eighteenth century of the Muslim states of Futa Jallon in the Guinea highlands and Futa Toro on the Senegal River.

Interview of Abd-Al Rahman from African Repository (May 1828)

The jihad movement continued into the nineteenth century, especially with the outbreak of war in 1804 in the Hausa states (northern Nigeria) under the leadership of Sheikh Usman dan Fodio. These wars in turn exacerbated political tensions in Oyo, which resulted in a Muslim uprising and the collapse of the Oyo state between 1817 and 1833. New strongholds were created at Ibadan, Abeokuta, and Ijebu, and the conflict intensified over attempts to replace or resurrect the Oyo state.

A Narrative of the Most Remarkable Particulars in the Life of James Albert Ukawsaw Gronniosaw, an African Prince by Gronniosaw, James Albert Ukawsaw and Shirley, Walter, 1725-1786

After 1700, the importation of firearms heightened the intensity of many of the wars and resulted in a great increase in the numbers of enslaved peoples. European forces intervened in some of the localized fighting and in warfare all along the Atlantic coast. They sought to obtain captives directly in battle or as political rewards for having backed the winning side. Working from their permanent colonies at Luanda, Benguela, and other coastal points, the Portuguese conducted joint military ventures into the hinterlands with their African allies.

A Narrative of the Life and Adventures of Venture, a Native of Africa by Smith, Venture, 1729?-1805

Africans also became enslaved through non-military means. Judicial and religious sanctions and punishments removed alleged criminals, people accused of witchcraft, and social misfits through enslavement and banishment. Rebellious family members might be expelled from their homes through enslavement. Human pawns, especially children, held as collateral for debt were almost always protected from enslavement by relatives and customary practices. However, debts and the collateral for those debts were sometimes subjected to illegal demands, and pawned individuals, especially children, were sometimes "sold" or otherwise removed from the watchful eyes of the relatives and communities that had tried to safeguard their rights.

Africans were also kidnapped, though kidnapping was a crime in most communities, and sold into slavery. Captives were sometimes ransomed, but this practice often encouraged the taking of prisoners for monetary rewards.

	The Interesting Narrative of the Life of Olaudah Equiano, or Gustavus Vassa, the African. by Written by Himself
	Some Memoirs of the Life of Job, the Son of Solomon the High Priest of Boonda in Africa by Thomas Bluett

As the slave trade destroyed families and communities, people tried to protect their loved ones. Various governments and communal institutions developed means and policies that limited the trade's impact. Muslims were particularly concerned with protecting the freedom of their co-religionists. Qur'anic law stated that those of the Faith born free must remain free. But this precept was often violated.

Throughout Africa, people of all beliefs tried to safeguard their own. Some offered themselves in exchange for the release of their loved ones. Others tried to have their kin redeemed even after they had been shipped away. Resistance took the form of attacks on slave depots and ships, as well as revolts in the forts, in barracoons, and on slave ships.

Song heard on Gorée Island, Senegal, in the eighteenth century from Voyage fait par ordre du roi en 1771 et 1772, en diverses parties de l'Europe, de l'Afrique et de l'Amerique by Jean Rene Antoine Verdun de la Crenne

But at a higher level, the political fragmentation - many small centralized states and federations governed through secret societies - made it virtually impossible to develop methods of government that could effectively resist the impact of the slave trade. Even the largest states, such as Asante and Oyo, were small by modern standards. Personal gain and the interests of the small commercial elites who dominated trade routes, ports, and secret societies also worked against the freeing of captives, offenders, and displaced children, who could easily end up in the slave trade.

Colonies Attempted, or Now Forming in Africa, on the Principles of Humanity, by the British, the Dates and the Swedes from An Essay on Colonization, Vol II by Wadström, Carl Bernhard