The Atlantic Crossing
So, what would induce two young men, eighteen and nineteen years of age, to get on a small ship and head off to a land that most knew only by rumor? The lack of economic prospects, surely, accounts for much of it. The economy was in tough shape. They were in a difficult societal position as dissenters. Food had been scarce the previous few years. They were from a large family and, as younger sons, probably not in line to inherit any land. By 1729, there would have been many mouths to feed in the family. One more factor needs to be added to this mix: that there were concerted efforts made by shipping companies to encourage such emigration.
Much of the impetus for American colonization during the 17th century had come from Englishmen who had received land grants in the colonies and were looking for settlers to work the land. These grantees saw the prospect of significant profits through the production and sale of raw materials which were to be sent back to England. To make this system work, they needed people to settle on the land and either raise the crops or cut down the timber that would be shipped back across the Atlantic. However, this work required much labor, and the families who initially settled in America usually could not provide for their own survival and also generate these materials without help. While black Africans were increasingly being imported as slaves during the 17th and early 18th centuries, they were used mainly in the southern colonies (as well as in the Caribbean and South America). The New England colonies used a few, but the Mid-Atlantic colonies came to rely more on indentured servants--people who had to borrow funds for their ocean passage and who would sign a contract to work for four years or so after arriving to pay off their debt. The general pattern was for ship owners (or captains) to advertise for and sign up a shipload of non-paying, but contracted, passengers. They would then sell those contracts to farmers and other people needing labor when the ships docked in America.
The voyage generally took eight to ten weeks and could be relatively pleasant or rather wretched, depending on the weather, the quality and quantity of food that was provided, and whether or not disease broke out among the passengers (who were packed in pretty tightly). Upon arriving at an American port (Philadelphia in the case of William and David) the servants would be paraded on deck to prospective buyers and their contracts sold at auction. Histories of this time report that approximately 90% of the Scots and Irish emigres came over using this arrangement.