The Great Migration from Ulster to America began in 1717. In some instances Ulster families had immigrated to the New World before 1717, but those instances were few and isolated. Not all of them succeeded. In 1636 a group left Ireland but had to return because of violent storms enroute. A group of Presbyterian families from Laggan had better luck in 1684 and safely accomplished their voyage. Here and there, over the years individual families made the trip across the Atlantic Ocean.
Some families left Ulster for religious reasons, but most left in response to economic hardships. The English Parliament began to impose trade restrictions on the manufacture and sale of woolen articles in the late-1690s. Up to that time, Ulster had thrived on her wool and linen industries and had prospered more than any other province in Ireland. The immigration of the Huguenots in the 1680s to Ulster had strengthened her already strong wool industry by introducing some new methods for the manufacture of linen from flax. The prosperity Ulster was experiencing was seen as a threat by the English who, in 1698, petitioned the King to protect their own interests. The Irish Parliament, at the King's urging, passed the Woolens Act in the following year. The Woolens Act prohibited the exportation of Irish wool and cloth to anywhere except England and Wales. The Woolens Act resulted in a period of economic depression throughout Ulster.
Coupled with the economic hardships spawned by the Woolens Act, was a legal practice known as rack-renting which was instituted in the early-1700s. Rack-renting was the practice whereby a renter could legally raise the rent when a lease had run out. Although that practice does not seem unusual in this day and age, it was quite a departure from the traditional during the Seventeenth and Eighteenth Centuries. The traditional practice was for a lease to run approximately thirty years with the option of being renewed at the same rate. The renter would be inclined to improve the property under the assumption that he would be able to reside there indefinitely and then pass the lease on to his own sons. Money was hard to come by and rack-renting forced many renters to default on their payments. A widespread hatred of the practice and those landlords who employed it swept through Ulster. Having received favorable reports from others who had gone to America, many families resolved to leave Ireland.
The thing that finally led to the Great Migration came in the form of a severe drought that stretched from 1714 to 1719. The drought affected not only did foodcrops, but also hindered the growing of flax and thereby adversely affected the linen industry. Lack of sufficient grass for grazing, and the disease known as rot, killed the sheep needed by the wool industry. It is often noted in a broad statement that the Europeans immigrated to the New World because of religious persecution, and that may well have been the reason for some of them. But the Ulster-Scots came primarily because of the droughts and the failing economy in their homeland.
There were five major waves of emigration from the Irish province of Ulster. It should be noted that there were very few instances recorded of any of the native Irish leaving their homeland; the Irish first immigrated to the United States after the mid-1800s when the failure of the potato crop caused widespread famine. The emigrants who left Ireland prior to the American Revolutionary War came solely from the province of Ulster. More than five thousand people emigrated from Ulster in 1717-1718. Those families sent back favorable reports, which helped to pave the way for future migrations. Between 1725 and 1729 there was another wave of emigration from Ulster, again induced primarily by the suffering caused by rack-renting. During that migration it was estimated that over six thousand people left Ulster in 1728 alone. In 1740 a major famine devastated Ireland and brought about the third major wave of emigration from Ulster. The fourth wave emigrated in 1754-1755, partly as a result of hardships occasioned by drought and partly because of an effort made by the governor of the province of North Carolina to attract settlers to that colony. Governor Dobbs had left Ulster himself, and his call was answered by many other Ulstermen. The last major wave of emigration occurred between 1771 and 1775. At least twenty-five thousand people are believed to have emigrated during this period. That great wave of departure from Ireland was motivated primarily by the eviction of so many families from county Antrim when the leases on the estate of the Marquis of Donegal expired and the settlers could not comply with the rack-renting demands. Altogether, approximately 200,000 people, primarily of Scottish descent and Presbyterian faith, left Ulster and sailed for America between 1717 and 1775.
The Ulster-Scots chose the colony of Pennsylvania as their destination in the New World. When considering which colony to make their new homes in, the Ulster- Scots really had only limited choices. The southern colonies were not very enticing with their slave labor and plantation system of agriculture. Nor was Maryland because it had been established as a Roman Catholic colony. Although not Catholic, New York had made it clear to earlier immigants that she would not tolerate religious diversity. Of the choices between New England and Pennsylvania, the earliest immigrants had been made to feel unwelcome at Boston, the primary port of entry. The single colony that welcomed the Ulster- Scots with open arms was Pennsylvania. As noted previously, Governor Dobbs of North Carolina invited fellow Ulster-Scots to settle in that colony, but that was only after Pennsylvania had become overly crowded with immigrants. In fact, that was one of the selling points the governor used to entice settlers southward from William Penn's colony.