It is a reasonable assumption that these three crossed the North Channel some time in the 1660s, giving themselves time enough to own property with hearths. Presumably the younger two had been born in the 1640s and the father about 1620. Certainly the spelling McIlhago was around in Ayrshire at that time. Robert Mc'Ilhago appears there in 1597. Another Robert McIlhago witnessed his grandson's baptism at Ayr in 1685. He could be a contemporary of either of the younger Ulster men, or indeed the father. One has to add that, though it is a good Scots name, there are no other Alexanders of whom I know in the Ayrshire family, and the next James to appear does so in about 1740.
It is of interest to speculate why three clan members, possibly with their families (or else why were they living in three separate properties in 1669?) may have chosen to migrate to Ulster in that decade. The clue could well be in the nature of the times which have come to be known as the 'Killing Times'. It is a reasonable assumption that the three men in the Hearth Money Rolls were Presbyterians, for the great majority of later clan members in Ulster were. 1660 saw the Restoration of the Monarchy when Charles II came to the throne. After the previous twenty years when Covenanting Presbyterianism was in the ascendancy, there was a violent return to earlier persecution.
It began in 1660 with many arrests and executions, then in 1661-2 came the ejection of hundreds of Presbyterian ministers from their parishes, who then had to preach, on both sides of the Channel, in remote fields and hillsides. In 1665-6 the battles between the royalist troops and the Covenanting bands were fought fiercely, not least in the south west of Scotland before spreading to the east and to Edinburgh. Throughout December 1666 a spate of bloody public executions of Covenanters took place across Scotland, though at Irvine and Ayr the official hangman refused to carry out his task. Although in the early '60s the ejected Ulster ministers and many followers had crossed to Scotland to join the Covenanters there, in late 1666 and early 1667 Ulster again became the refuge for many, especially from the west of Scotland.
This in brief was the background to what was to become known as the 'Killing Times' and perhaps was the main reason why first James McElhago, a sea captain of Irvine, chose to spend the mid to late '60s in America, and also why Alex and Allexander McIlhago and James McIlhaga migrated just across the North Channel to Ulster and to reestablish themselves in the parish of Doagh Grange.