Before the 19th century, most of the Irish in the U.S. claiming Irish ancestry were of Scotch-Irish descent. Scotch-Irish descend from Scottish Presbyterians who settled in Ireland between 1608 and 1697. They are also called Ulster Presbyterians after the county in which many of them settled. In the 1700s, many came to America and settled in Pennsylvania and the Appalachian region. Many more immigrated to the U.S. in the 19th century.