Life in the American wilderness was nasty, brutish, and short for the earliest Chesapeake settlers; malaria, dysentery, and typhoid took a cruel toll, cutting ten years off the life expectancy of newcomers (half of people born in early Virginia/Maryland did not survive to twenty).
The disease-ravaged settlements of the Chesapeake grew only slowly in the seventeenth century, mostly through fresh immigration from England; the majority of immigrants were single men in their late teens and early twenties, and most perished soon after arrival. And most had left their women behind, when they set sail for the new world.
Surviving males competed for the affections of the extremely scarce women, whom they outnumbered nearly six to one in 1650. Although they were still outnumbered by three to two at the end of the century, eligible women did not remain single for long. Families were both few and fragile in this ferocious environment; most men could not find mates and most marriages were destroyed by the death of a partner within seven years. Weak family ties showed in many pregnancies among unmarried young girls (in one area, a third of those married were pregnant).
Yet despite these hardships, the Chesapeake colonies struggled on; the native-born inhabitants eventually acquired immunity to the killer diseases that had ravaged the original immigrants. The presence of more women allowed more families to form and by the end of the seventeenth century, the white population of the Chesapeake was growing on the basis of its own birthrate. At the beginning of the eighteenth century, Virginia, with some 59,000 people was the most populous colony and Maryland, with about 30,000 people was the third largest colony (after the Massachusetts colony).