6 Crude rates of persistence for tithables were as follows in Northampton Co., Va.: 1664-74, 45%; 1665-75, 43%; 1666-76, 46%; 1667-77, 42%. In Surry Co., Va., they were: 1668-78, 46%; 1678-88; 47%; 1688-98, 45%. Comparisons with rates of persistence in New England are problematical. The unit of study is the county in Virginia and the town in New England. The county tended to be larger than the town. As the analytic unit increases in size, the persistence rate rises too, ceterus paribus. In consequence, the difference between Massachusetts and Virginia in rates of crude persistence was actually greater than appears here. But mortality was higher in the Chesapeake than in New England; refined persistence rates (which cannot yet be computed for Virginia) would be closer in the two regions than crude persistence rates tended to be. Sources include Kevin Kelly, “Economic and Social Development of Seventeenth Century Surry County, Virginia” (thesis, Univ. of Washington, 1972); Edmund S. Morgan, American Slavery, American Freedom (New York, 1975), 427.

7 Allan Kulikoff reports the following refined migration rates for Prince George’s County, Maryland, 1733-43: householders owning land and slaves, 15%; householders owning land or slaves, 29%; long-term residents, owning neither, 39%; recent immigrants, owning neither, 58%; sons of tenants, 65%; laborers without kin ties in county, 75%; Kulikoff, Tobacco and Slaves, 93.

8 Peter Laslett discovered two population lists for the parish of Cogenhoe, Northamptonshire, an area that contributed heavily to the peopling of Virginia. The crude persistence rate in Cogenhoe from 1618 to 1628 was 48%, almost exactly the same as in Northampton County, Virginia. See Peter Laslett and John Harrison, “Clayworth and Cogenhoe,” in H. E. Bell and R. L. Ollard, eds., Historical Essays Presented to David Ogg (1963); a revised and expanded edition appears in Peter Laslett, Family Life and Illicit Love in Earlier Generations; Essays in Historical Sociology (Cambridge, 1977), 50-101.

9 For evidence that the size of the neighborhood was similar in the Chesapeake and the west of England, see Horn, “Social and Economic Aspects of Local Society in England and the Chesapeake,” 286.