1718 -- The first major migration of Scots-Irish to America is a group with the Reverend James McGregor who migrate from County Londonderry, Ireland, to New England. Scots-Irish -- mostly free men but some indentured servants -- continue to arrive in the American Colonies throughout the 18th century. The majority of the Scots-Irish who come to America in the Colonial period settle in Pennsylvania, Virginia and the Carolinas, but there is significant Scots-Irish settlement in each of the 13 American Colonies. The parents of Andrew Jackson, seventh U.S. president, were Scots-Irish immigrants. (Library of Congress)