The Transatlantic slave trade forcibly connected Africa and the Americas. Through horrific violence and unchecked avarice, the perpetrators of this trade facilitated ethnic exchange in the regions of the Atlantic World most connected to the slave trade. Captive Africans forced into the trade came from all over West and Central Africa, as did the African traders who sold them to a similarly diverse group of European and American buyers. In the New World, enslaved Africans forced to migrate across the ocean interacted with Native populations, Europeans and European-descended settlers, as well as Afro-descendant populations already present in the Americas. Our panel analyzes the ethnic exchanges associated with the slave trade across the long arc of Atlantic World history and on both sides of the Atlantic Ocean. Ranging from the earliest days of Spanish colonization in the Caribbean to the age of abolition in Sierra Leone, we discuss the myriad ways in which the evolution of the form and function of the slave trade impacted ethnic exchanges in regions heavily associated with slave trading. Specifically, our presentations focus on the frontier society of Spanish Jamaica in the 17^th century, the material economy of the 18^th century Bight of Biafra, piracy and illegal slave trading in the early 19^th century Caribbean, and the resettlement of liberated Africans in Sierra Leone in the 19^th century. These topics reflect our respective temporal and geographic specializations within Atlantic World history and allow our panel to consider the Transatlantic slave trade from its beginnings until its legal abolition. While our individual topics are separated by thousands of miles and hundreds of years, together they tell a rich story of how the slave trade tore people apart and brought them together, destroying some ethnic groups while forcing new ones into existence. Across space and time, our panel demonstrates that the combined wickedness and seemingly irresistible profitability of the slave trade resulted in the convergence of previously unrelated groups of people in the areas touched by the trafficking of enslaved Africans. By focusing on such a diverse group of times and places, our panel collectively shows that there was not a simple answer to the question of how the slave trade impacted ethnic exchange in the Atlantic World. We show that as the trade changed so too did the ways it forced different groups of people to interact with one another, resulting in an array of outcomes ranging from new group identities such as the Jamaican Maroons, new types of ethnic tension such as that between resettled liberated Africans and the indigenous population of Sierra Leone, or syncretic societies such as the Seminoles in Florida. Together, we present a history of lives and communities shaped and reshaped by the horrors and longevity of the slave trade. Our panel presents the slave trade not as the backdrop of Atlantic history but as the living engine of it, the force directly responsible for the diversity and migration that made the Atlantic World such a unique chapter of world history.