The British Isles
In 1707, England and Scotland effectively merged into the United Kingdom. Prior to that, the greatest majority of all settlers in the American colonies were simply English, which of course included the Welsh, who had been long-before integrated into the English system and culture (although they continue to keep a separate culture even now).
Ireland did not join the United Kingdom until 1808, and there was very little opportunity for the Irish to make their way to the colonies, as it was for the Scots before 1707. Scots did emigrate to the colonies prior to 1707, but their numbers were very few, and those were already "ok" in the eyes of the English. Likewise, the Irish also managed to emigrate to the colonies prior to 1808, but their numbers were even smaller than the Scots.
The majority of seventeenth-century English emigrants were poor, young, single men, lacking good prospects in the mother country, gambling their lives as indentured servants in the Chesapeake, Carolinas, or West Indies, where the warmer climate permitted plantation crops that demanded—and generated the profits that permitted—the importation of laborers.
In sharp contrast, most of the New England colonists could pay their own way and emigrated as family groups. They also enjoyed a more even balance between the sexes. At mid-century, the New England sex ratio was six males for every four females, compared to four men for every woman in the southern colonies. This more even balance encouraged a more stable society and faster population growth.
New England’s healthier population sustained a rapid growth through natural increase, while in the southern colonies and West Indies, population growth depended on human imports. During the seventeenth century, New England received only 21,000 emigrants—a fraction of the 120,000 transported to the southern colonies or the 190,000 who colonized the West Indies. Yet in 1700, New England’s colonial population of 91,000 exceeded the 85,000 whites in the southern colonies and the 33,000 white residents in the West Indies.
Scots emigration to the colonies soared to 145,000 between 1707 and 1775. Generally poorer than the English, the Scots had greater incentives to emigrate, and the union of 1707 (when England and Scotland agreed to form the United Kingdom) gave them legal access to all of the colonies. The Scottish diaspora flowed in three streams: Lowland Scots, Highland Scots, and Ulster Scots. Assimilated to English ways, the Lowland Scots were primarily skilled tradesmen, farmers, and professionals pulled by greater economic opportunity in America.
They usually emigrated as individuals or single families, then dispersed in the colonies and completed their assimilation to Anglo-American ways. In 1746, the British army brutally suppressed a rebellion in the Highlands (the end of the Jacobite Rebellion), and Parliament outlawed many of their traditions and institutions. At mid-century, the common Highlanders also suffered from a pervasive rural poverty worsened by the rising rents demanded by their callous landlords. The emigrants primarily came from the relatively prosperous peasants, who possessed the means to emigrate and feared remaining in the Highlands, lest they fall into the growing ranks of the impoverished.
After 1750, emigration brokers and ambitious colonial land speculators frequented the northwest coast of Scotland to procure Highland emigrants. The brokers and speculators recognized that the poor but tough Highlanders were especially well-prepared for the rigors of a transatlantic passage and colonial settlement. Confined to cheap (and often dangerous) lands, the Highland Scots clustered in frontier valleys, especially along the Cape Fear River in
North Carolina, the Mohawk River of New York, and the Altamaha River in Georgia. By clustering, they preserved their distinctive Gaelic language and Highland customs, in contrast to the assimilation practiced by the Lowland emigrants.
Nearly half of all so-called Scots emigrants came from Ulster, in Northern Ireland, which their parents and grandparents had colonized during the 1690s. Like the Highlanders, the Ulster Scots sought to escape from deteriorating conditions. During the 1710s–20s they clashed with the Irish Catholic and endured a depressed market for their linen, several poor harvests, and increasing rents. The Ulster Scots emigration to the colonies began in 1718 and accelerated during the 1720s. The destitute sold themselves into indentured servitude, while the families of middling means liquidated their livestock to procure the cost of passage. Of course, most of the Ulster Scots remained at home, preferring the known hardships of Northern Ireland to the uncertain prospects of distant America.
The Ulster Scots emigrated in groups, generally organized by their Presbyterian ministers, who negotiated with shippers to arrange passage. Once in the colonies, the Ulster Scots gravitated to the frontier, where land was cheaper, enabling large groups to settle together. In the colonies, they became known as “the Scots-Irish.” At first, the Ulster Scots emigrated to Boston, but some violent episodes of New English intolerance persuaded most, after 1720, to head for Philadelphia, a more welcoming seaport in a more tolerant colony. More sparsely settled than New England, Pennsylvania needed more settlers to develop and defend the hinterland.
Beginning in the 1740s, as the seeds of the upcoming French and Indian War (1756-1763) were being sowed with more and more Indian raids along the Pennsylvania frontier, many Scots-Irish took to the Great Wagon Road from Pennsylvania, through the Shenandoah valley, down to North Carolina and South Carolina. The Scots-Irish immigrated to the Carolinas in droves, from the very-late 1730s to the 1760s, quickly filling up the Midlands and Backcountry of South Carolina, and the Piedmont up to the Appalachian mountains in North Carolina.