03/17/2026
Some thoughts about Ireland on St. Patrick's Day
On St. Patrick's Day, most people know they have Irish blood. Very few know why their ancestor actually left.
Today millions of people will feel some version of Irishness without being able to say much about where it actually came from. I don't mean that critically. It's just how these things work across generations. The connection persists long after the details fade.
But if you're curious enough to actually research that connection, the most useful starting point isn't a name or a county. It's understanding when your ancestor left Ireland, and what was happening in Ireland when they went.
Irish emigration didn't happen in a single surge. It moved in distinct waves across nearly three centuries, each driven by different forces, each producing a different kind of emigrant. Knowing which wave your ancestor was part of tells you what their life probably looked like, what route they likely took, what records were created at each point in the journey, and what you're realistically likely to find today.
1. Before the Famine, leaving Ireland required money
This surprises people. The common picture of Irish emigration is shaped almost entirely by the Famine, and it assumes that emigration was something that happened to the very poorest. For most of the period before 1845, that picture is largely wrong.
The first substantial wave of Irish emigration to North America began in the early 18th century and ran through to the American Revolution. These were mostly Ulster Presbyterian families, from counties Antrim, Down, Derry, and Tyrone, and they left primarily because of rent increases on land they'd been farming for generations, restrictions on Presbyterian worship, and competition from English textile imports that was destroying the domestic weaving trade. They were skilled people. Textile workers, farmers, craftsmen. They departed from Belfast, Derry, and Newry. They settled in Pennsylvania, Virginia, and the Carolinas. They're the ancestors often referred to in America as Scots-Irish.
What pushed the Catholic majority of Ireland to emigrate in larger numbers came later, in the decades between roughly 1815 and 1845. The Penal Laws had eased. Shipping routes from Dublin and Cork had become more regular. Word was coming back from America that there was work. But passage cost money, and most of rural Ireland was living very close to subsistence. In this period, emigration was still largely limited to people who had some resources. Seasonal labourers who'd saved money from working in Britain. Families with enough land to sell a portion of it. Some landlords were paying tenants to leave as a way of consolidating their holdings. The very poorest, the people with nothing at all, mostly could not go.
That changed with the Famine.
2. The Famine (1845-1852)
The potato blight struck in the autumn of 1845. By 1847, what was already a crisis had become a catastrophe. Approximately 1.5 million people left Ireland during the Famine years. Another million died.
The emigration was not uniform across Ireland. Western counties were hit hardest. Some local areas lost more than 30 percent of their population. Ulster, with its more diverse economy, was less severely affected. Coastal areas saw earlier emigration than inland ones because the ports were closer. Urban centres like Cork, Dublin, and Liverpool became gathering points for people trying to get out.
The emigrant profile shifted as the crisis deepened. Early Famine emigrants often still had some resources and were following established routes to relatives who'd already gone abroad. By 1847 and 1848, it was much more destitute families leaving, sometimes funded by assisted emigration schemes run by landlords who simply wanted the land cleared. Whole family groups went together in a way that earlier emigration rarely saw.
The ships were overcrowded. Many had been timber cargo vessels converted hurriedly for passenger use. On the worst of them, mortality rates reached 20 percent or higher. People arrived sick, having buried family members at sea. They arrived in Quebec, in Boston, in New York, in Liverpool, with very little. They settled in cities because they had no money to move further. The Irish communities that formed in Boston's North End, in New York's Five Points, in Liverpool's docklands, were built largely by Famine survivors who had no intention of staying but no resources to go anywhere else.
3. The leaving didn't stop when the Famine ended
This is one of the less understood parts of the story. The Famine created patterns that continued well past 1852. Chain migration took hold. One person went, found work, sent money back, and the next sibling followed. Then the next. Some Irish counties continued to lose population through emigration all the way to 1971. Not because people were still starving, but because the pattern had become self-sustaining. America was where you went. Australia was where you went. England was where you went. Staying was the unusual choice.
My own family is an example of this. On my mother's side, nine of ten siblings emigrated in the 1950s, to Canada, the United States, and Britain. Four of them eventually returned. On my father's side, all four siblings went to England in the same decade, and within twenty years all four had come home. What drove them by the 1950s had nothing to do with famine. It was economics, and opportunity, and the gravitational pull of wherever the cousins already were.
4. Why the timing matters for your research
Knowing roughly when your ancestor left places them in a context that shapes everything else you look for.
A pre-Famine Catholic emigrant probably had more resources than you might assume. An Ulster Presbyterian family leaving in the 1720s likely departed from Belfast or Derry and settled in Pennsylvania or Virginia. A Famine emigrant from Leinster may have crossed to Liverpool first and continued from there, rather than sailing directly from an Irish port. Someone leaving after 1853 with a job arranged in advance is a different kind of emigrant again. Each of these calls for a different research approach.
The timing also shapes which records were created and where they're held. Passenger lists from Irish ports before 1890 are extremely limited and survive poorly. But destination records can often compensate. Naturalisation papers filed in American courts, particularly from the late 19th century onwards, sometimes record the exact county or parish of birth in Ireland. Canadian border crossing records can be revealing. Death certificates filed in the destination country occasionally name a specific Irish location. Before searching any Irish record, exhausting the records created after your ancestor arrived somewhere else is often the more productive starting point.
It also shapes who to look for alongside your ancestor. Famine emigration often moved family groups together, or in quick succession over a year or two. If you find one sibling in Boston in 1848, there's a reasonable chance another appears in New York or Philadelphia around the same time. Chain migration means that the people who settled near your ancestor often came from the same townland. Neighbours in an Irish-American city were frequently neighbours in Ireland first. Working the community around your ancestor is often as productive as working the family directly.
Some free resources for tracing the journey: FindMyPast has passenger lists and records from assisted emigration schemes. Castle Garden records at archives.gov cover arrivals to New York from 1820 to 1892. Ellis Island records run from 1892 through 1954. Library and Archives Canada has digitised records of Irish immigrants, particularly from the Famine years. For the Irish end of the journey, AskAboutIreland has Griffith's Valuation from the 1850s, which shows which families were still in Ireland after the Famine and which townlands had emptied out entirely.
The story of why your ancestor left is also the story of what they left behind. That's worth knowing.
If you're working on Irish ancestry, I'm curious - which wave does your ancestor fall into? And did knowing the timing change how you approached the research?
