The Atlantic Slave Trade: A Census

9. Major Trends

CHAPTER 9 MAJOR TRENDS It is now possible to look at the long-term movement of the Atlantic slave trade over a period of more than four centuries. Table 77 sums up the pattern of imports for each century, while Fig. 26 shows the same data drawn as a graph to semi-logarithmic scale. Together, these data make it abundantly clear that the eighteenth century was a kind of plateau in the history of the trade-the period when the trade reached its height, but also a period of slackening growth and beginning decline. The period 1741-1810 marks the surr:mit of the plateau, when the long-term annual average rates of delivery hung just above 60,000 a year. The edge of the plateau was reached, however, just after the Peace of Utrecht in 1713, when the annual deliveries began regularly to exceed 40,000 a year, and the permanent drop below 40,000 a year did not come again until after the 1840's. Thus about 60 per cent of all slaves delivered to the New World were transported during the century 1721-1820. Eighty per cent of the total were landed during the century and a half, 1701-1850. The higher rates of growth, however, came at earlier phases of the trade. The highest of all may have been an apparent growth at the rate of 3.3 per cent per year between the last quarter of the fifteenth century and the first quarter of the sixteenth, but the data for this early period are too uncertain for confidence in this figure. In the smoothed-out long-term annual averages of the graph, the growth of the trade was remarkably constant at a 265 266 THE ATLANTIC SLAVE TRADE Fig. 26. Major trends of the Atlantic slave trade, in annual average number of slaves imported. Fig. by UW Cartographic Lab. Data from Tables 33, 34, 65, 67. remarkably uniform rate over more than two centuries. Two periods of stability or possible decline occur, one between the first and second quarters of the sixteenth century and again between 1601-25 and 1626-50. Aside from these periods, the growth rate was an overall 2.2 per cent per year in the last half of the sixteenth century and the first quarter of the seventeenth, and at about the same rate during the equivalent period a century later. But during the first four decades of the eighteenth century, the growth rate was 0.7 per cent. These trends are not surprising. They run parallel to the growth of the South Atlantic System traced in the literature on qualitative evidence. The nineteenth-century portion of the curve is less predictable from the present literature, but hardly surprising. The slave trade began to decline in the 1790's-not after 1808 with the legal abolition of the British trade-and this trend shows more clearly and precisely in the combined Anglo- Maior Trends 267 French-Portuguese shipping data (Table 63 and Fig. 15) than it does in the longer-term data of Fig. 26. One of the common older views of the slave trade holds that a last burst of imports took place between about 1802 and 1807, as planters sought to fill out their slave gangs before the trade became illegal. This pattern may be true of imports into the Anglo-Saxon territories, but not for the slave trade as a whole. Instead, the general trend shows a drop to the 1810's, then a rise in the 1820's. At first glance, the removal of British shipping from the trade in 1808 made no difference at all in the totals transported. But this interpretation is probably mistaken. In the eighteenth century, warfare was the really important influence on the short-run rise and fall of the slave trade. There is no reason to expect this pattern to have changed at the end of the century. The drop of the 1790's seems to be accountable to the Napoleonic Wars, and it continued into the decade of the 1800's. After the wars, and especially after such a long period of warfare, an enormous backlog of demand would be expected, and the trade might well have shot up to meet that demand-had it not been for British abolition and the early work of the anti-slave-trade patrols at sea. The trade recovered somewhat in the...