A strong immigration early set in from the north of Ireland to the western parts of Scotland. It was under no leadership, but more in the nature of an overflow, or else partaking of the spirit of adventure. This was accelerated in the year 503, when a new colony of Dalriadic Scots, under the leadership of Fergus, son of Eric, left Ireland and settled on the western coast of Argyle and the adjacent isles. From Fergus was derived the line of Scoto-Irish kings, who finally, in 843, ascended the Pictish throne.

The inhabitants of Ireland and the Highlands of Scotland were but branches of the same Keltic stock, and their language was substantially the same. There was not only more or less migrations between the two countries, but also, to a greater or less extent, an impinging between the people.

Ulster, the northern province of Ireland, is composed of the counties of Antrim, Armagh, Cavan, Donegal, Down, Fermanagh, Londonderry, Monaghan and Tyrone. Formerly it was the seat of the O'Neills, as well as the lesser septs of O'Donnell, O'Cahan, O'Doherty, Maguire, MacMahon, etc. The settlements made by the earlier migrations of the Highlanders were chiefly on the coast of Antrim. These settlements were connected with and dependent on the Clandonald of Islay and Kintyre. The founder of this branch of that powerful family was John Mor, second son of "the good John of Islay," who, about the year 1400, married Majory Bisset, heiress of the Glens, in Antrim, and thus acquired a permanent footing. The family was not only strengthened by settling cadets of its own house as tenants in the territory of the Glens, but also by intermarriages with the families of O'Neill, O'Donnell, and others. In extending its Irish possessions the Clandonald was brought into frequent conflicts and feuds with the Irish of Ulster. In 1558 the Hebrideans had become so strong in Ulster that the archbishop of Armagh urged on the government the advisability of their expulsion by procuring their Irish neighbors, O'Donnell, O'Neill, O'Cahan, and others, to unite against them. In 1565 the MacDonalds suffered a severe defeat at the hands of Shane O'Neill, earl of Tyrone. The Scottish islanders still continued to exercise considerable power. Sorley Buy MacDonald, a man of great courage, soon extended his influence over the adjacent territories, in so much so that in 1575-1585, the English were forced to turn their attention to the progress of the Scots. The latter having been defeated, an agreement was made in which Sorley Buy was granted four districts. His eldest son, Sir James MacSorley Buy, or MacDonell of Dunluce, became a strenuous supporter of the government of James on his accession to the British throne.

In the meantime other forces were at work. Seeds of discontent had been sown by both Henry VIII, and his daughter Elizabeth, who tried to force the people of Ireland to accept the ritual of the Reformed Church. Both reaped abundant fruit of trouble from this ill-advised policy. Being inured to war it did not require much fire to be fanned into a flame of commotion and discord. Soon after his accession to the English throne, James I caused certain estates of Irish nobles, who had engaged in treasonable practices, to be escheated to the crown. By this confiscation James had at his disposal nearly six counties in Ulster, embracing half a million of acres. These lands were allotted to private individuals in sections of one thousand, fifteen hundred, and two thousand acres, each being required to support an adequate number of English or Scottish tenantry. Protestant colonies were transplanted from England and Scotland, but chiefly from the latter, with the intent that the principles of the Reformation should subdue the turbulent natives. The proclamation inviting settlers for Ulster was dated at Edinburgh, March 28, 1609. Great care was taken in selecting the emigrants, to which the king gave his personal attention. Measures were taken that the settlers should be "from the inward parts of Scotland," and that they should be so located that "they may not mix nor intermarry" with "the mere Irish." For the most part the people were received from the shires of Dumbarton, Renfrew, Ayre, Galloway, and Dumfries. On account of religious persecutions, in 1665, a large additional accession was received from Galloway and Ayre. The chief seat of the colonization scheme was in the county of Londonderry. The new settlers did not mix with the native population to any appreciable extent, especially prior to 1741, but mingled freely with the English Puritans and the refugee Huguenots. The native race was forced sullenly to retire before the colonists. Although the king had expressly forbidden any more of the inhabitants of the Western Isles to be taken to Ulster, yet the blood of the Highlander, to a great degree, permeated that of the Ulsterman, and had its due weight in forming the character of the Scotch-Irish. The commotions in the Highlands, during the civil wars, swelled the number to greater proportions. The rebellions of 1715 and 1745 added a large percentage to the increasing population. The names of the people are interesting, both as illustrating their origin, and as showing the extraordinary corruptions which some have undergone. As an illustration, the proscribed clan MacGregor, may be cited, which migrated in great numbers, descendants of whom are still to be found under the names of Grier, Greer, Gregor, etc., the Mac in general being dropped; MacKinnon becomes McKenna, McKean, McCannon; Mac Nish is McNeice, Menees, Munnis, Monies, etc.

The Scotch settlers retained the characteristic traits of their native stock and continued to call themselves Scotch, although molded somewhat by surrounding influences. They demanded and exercised the privilege of choosing their own spiritual advisers, in opposition to all efforts of the hierarchy of England to make the choice and support the clergy as a state concern.

From the descendants of these people came the Scotch-Irish emigrants to America, who were destined to perform an important part on the theatre of action by organizing a successful revolt and establishing a new government. Among the early emigrants to the New World, although termed Scotch-Irish, and belonging to them we have such names as Campbell, Ferguson, Graham, McFarland, McDonald, McGregor, McIntyre, McKenzie, McLean, McPherson, Morrison, Robertson, Stewart, etc., all of which are distinctly Highlander and suggestive of the clans.

On the outbreak of the American Revolution the thirteen colonies numbered among their inhabitants about eight hundred thousand Scotch and Scotch-Irish, or a little more than one-fourth of the entire population. They were among the first to become actively engaged in that struggle, and so continued until the peace, furnishing fourteen major-generals, and thirty brigadier generals, among whom may be mentioned St. Clair, McDougall, Mercer, McIntosh, Wayne, Knox, Montgomery, Sullivan, Stark, Morgan, Davidson, and others. More than any other one element, unless the New England Puritans be excepted, they formed a sentiment for independence, and recruited the continental army. To their valor, enthusiasm and dogged persistence the victory for liberty was largely due. Washington pronounced on them a proud encomium when he declared, during the darkest period of the Revolution, that if his efforts should fail, then he would erect his standard on the Blue Ridge of Virginia. Besides warring against the drilled armies of Britain on the sea coast they formed a protective wall between the settlements and the savages on the west.

Among the fifty-six signers of the Declaration of Independence, nine were of this lineage, one of whom, McKean, served continuously in Congress from its opening in 1774 till its close in 1783, during a part of which time he was its president, and also serving as chief justice of Pennsylvania. The chairman of the committee that drafted the constitution of the United States, Rutledge, was, by ancestry, Scotch-Irish. When the same instrument was submitted, the three states first to adopt it were the middle states, or Delaware, Pennsylvania and New Jersey, so largely settled by the same class of people.

Turning again specifically to the Scotch-Irish emigrants it may be remarked that they had received in the old country a splendid physique, having large bones and sound teeth, besides being trained to habits of industry. The mass of them were men of intelligence, resolution, energy, religious and moral in character. They were a God-fearing, liberty-loving, tyrant-hating, Sabbath-keeping, covenant-adhering race, and schooled by a discipline made fresh and impressive by the heroic efforts at Derry and Enniskillin. Their women were fine specimens of the sex, about the medium height, strongly built, with fair complexion, light blue or grey eyes, ruddy cheeks, and faces indicating a warm heart, intelligence and courage; and possessing those virtues which constitute the redeeming qualities of the human race.

These people were martyrs for conscience sake. In 1711 a measure was carried through the British parliament that provided that all persons in places of profit or trust, and all common councilmen in corporations, who, while holding office, were proved to have attended any Nonconformist place of worship, should forfeit the place, and should continue incapable of public employment till they should depose that for a whole year they had not attended a conventicle. A fine of £40 was added to be paid to the informer. There were other causes which assisted to help depopulate Ulster, among which was the destruction of the woolen trade about 1700, when twenty thousand left that province. Many more were driven away by the Test Act in 1704, and in 1732. On the failure to repeal that act the protestant emigration recommenced which robbed Ireland of the bravest defenders of English interests and peopled America with fresh blood of Puritanism.