"People from the north of England, Scotland, and northern Ireland made up much of the migration to the western frontier regions of the early American colonies, especially to the rugged mountainous areas. The northern Irish migrants were mainly Scotch-Irish, descendants of people from Scotland who had moved to Ireland in earlier centuries. Most of the Irish in America before the nineteenth century were actually Scotch-Irish. Northern Irish migration peaked between the 1750’s and the early 1770’s, with an estimated 14,200 people from northern Ireland reaching America from 1750 to 1759, 21,200 from 1760 to 1769, and 13,200 in the half-decade leading up to the American Revolution. Most of the Scots migration took place from 1760 to 1775, when about 25,000 new arrivals came to the colonies. The counties of North England, bordering Scotland, experienced a series of crop failures that were especially severe in 1727, 1740, and 1770. Each of these crop failures resulted in famine that sent successive waves of immigrants to America. Together, the Scottish, Scotch-Irish, and North English immigrants probably made up 90 percent of the settlers in the back country of America. Arriving after the lands along the eastern coast had been taken, these hardy individuals made up the original American frontier folk."