Based on data from probate inventories we construct and analyze an annual time series of slave prices for South Carolina from 1722 to 1809. Comparison of South Carolina slave prices with those in other parts of the Western Hemisphere and the relationship between slave prices and slave imports indicate that while the long-run supply of slaves was highly elastic, over periods of one to two decades the supply curve was upward sloping. Comparison of our slave price series with an index of agricultural export prices indicates that labor productivity growth in agriculture was modest over the eighteenth century.