This book describes the experiences of Irish emigrants from the 1700’s up to and including the entire 20th century. Not only does Dolan describe what life would have been like for the Irish who did cross the pond, he also discusses, in great detail, the conditions that caused many people to leave Ireland in the first place. And, no, much of it had very little to do with potatoes. While the largest number of people left Ireland in the Famine Years, many were already in the New World before the revolution, and many emigrated after the Civil War. Even after they emigrated, many Irish kept up their connections with their native land.
So, if it wasn’t because of the potato famine, why did they emigrate? In the early part of the settlement of the North American continent, many Irish emigrated due to religious repression and a poor economy. But also, many of the colonies were looking for more people, and were offering land and other assistance to those who moved there. This early immigration lasted until about the 1840’s, and was split between Catholics and Protestants. While life as a Catholic was difficult in Ireland, it was only slightly better for Catholics in the colonies, with the possible exception of Maryland.
The immigration story we are all most familiar with has to do with the Potato Famine, which started in 1845. The failure, for several consecutive years, of the main crop that sustained much of the population was devastating. Many people died of starvation, and many died at least partially due to the slow and inadequate response of the British government to offer aid. Many people emigrated just to avoid starvation. But another part of the problem was that tenants who were unable to pay their rents were evicted from their lands. They had very little incentive to stay after that. And they probably knew people who were already in America.
If this was your family, how would you research them? Dolan does a good job of not only giving a broad overview of Irish immigrants, but he also mentions quite a few by name. While your ancestor is probably not mentioned, their lives might parallel someone who is. While you will need to trace your line back to their home country in the usual ways, if you find you have Irish roots, you might check out GENUKI, (https://www.genuki.org.uk/index.php) a free site that focuses on UK and Irish genealogy.