The ship grew larger and more terrifying with every vigorous stroke of the paddles. The smells grew stronger and the sounds louder — crying and wailing from one quarter and low, plaintive singing from another; the anarchic noise of children given an underbeat by hands drumming on wood; the odd comprehensible word or two wafting through: someone asking for menney, water, another laying a curse, appealing to myabecca, spirits.
An estimated 12.5 million people endured some version of this journey, captured and shipped mainly from the western coast of Africa to the Western Hemisphere during the four centuries of the trans-Atlantic slave trade. Of that number, about 10.7 million survived to reach the shores of the so-called New World.
It is thanks to decades of painstaking, difficult work that we know a great deal about the scale of human trafficking across the Atlantic Ocean and about the people aboard each ship. Much of that research is available to the public in the form of the SlaveVoyages database. A detailed repository of information on individual ships, individual voyages and even individual people, it is a groundbreaking tool for scholars of slavery, the slave trade and the Atlantic world. And it continues to grow. Last year, the team behind SlaveVoyages introduced a new data set with information on the domestic slave trade within the United States, titled “Oceans of Kinfolk.”
The systematic effort to quantify the slave trade goes back at least as far as the 19th century. For example, in the 1888 edition of the second volume of his “History of the United States of America, From the Discovery of the American Continent,” the historian George Bancroft estimates “the number of negroes” imported by “the English into the Spanish, French, and English West Indies, and the English continental colonies, to have been, collectively, nearly three million: to which are to be added more than a quarter of a million purchased in Africa, and thrown into the Atlantic on passage.” He adds later, “After every deduction, the trade retains its gigantic character of crime.”
In 1958, the economic historians Alfred H. Conrad and John R. Meyer transformed the study of slavery — and of economic history more broadly — with the publication of “The Economics of Slavery in the Ante Bellum South.” Their methods, which relied on statistical data and mathematical analysis, revolutionized the field.