During the past few years new measures of growth have begun to emerge for the colonial period in American history which allow us to understand more fully the pace and pattern of long-run economic growth. This essay summarizes what we know about colonial growth and discusses rates of growth during the seventeenth and eighteenth centuries. After summarizing previous work on the subject, the paper estimates eighteenth-century agricultural productivity in one New England county. Data on total wealth, livestock, crops, land, and agricultural capital are generated from estate inventories. A consumer price index for the period also is constructed. From these data it appears that the seventeenth century experienced growth comparable to modern times, whereas the eighteenth century was a bleak period in our history. Although real wealth per inventory grew at a rate of 0.5 percent per year during the eighteenth century, agricultural productivity declined at a rate of 0.8 percent.