Hence the fields when rapidly exhausted by successive cropping in tobacco were as a rule abandoned to broomsedge and scrub timber while new and still newer grounds were cleared and cropped.

Each estate therefore, if its owner expected it to last a lifetime, must comprise an area in forestry much larger than that at any one time in tillage.

The great reaches of the bay and the deep tidal rivers, furthermore, afforded such multitudinous places of landing for ocean-going ships that all efforts to modify the wholly rural condition of the tobacco colonies by concentrating settlement were thwarted.

It is true that Norfolk and Baltimore grew into consequence during the eighteenth century; but the one throve mainly on the trade of landlocked North Carolina, and the other on that of Pennsylvania.

Not until the plantation area had spread well into the piedmont hinterland did Richmond and her sister towns near the falls on the rivers begin to focus Virginia and Maryland trade; and even they had little influence upon life on the tidewater peninsulas.
[Footnote 20: Bruce, _Economic History of Virginia_, II, 88.] The third tobacco-producing colony, North Carolina, was the product of secondary colonization.