In the late1960s and early 70s, poets were interested in the way poems sounded. They were trying in their poems to pick up and improvise on the sound patterns of ordinary speech. A way to catch that was to eliminate punctuation and capital letters – both late additions to the art of writing – and focus on the plain words and how you lay them out in a line and how that changes the rhythm and the emphasis of those words. I am comfortable with that – as a way of writing and of reading my poems.

I have to add though that when I was teaching at Southern Illinois University in East St. Louis, many of my students wrote out of an oral tradition. To understand their papers, you read them outloud. I was ready to appreciate that because the rivermen had that same kind of skill with the spoken language. At this time I was also reading works by Tudor preachers, men out of the Latin tradition who were eloquent Latinists and knew the flowers of rhetoric as handed down from the Greeks and Romans. But these men were writing before the grammarians structured the English language on a Latin base (so we can't put prepositions at the end of sentences because Latin does not have post-positions) and before the printers, to make it easier to set type, standardized spelling. So I have inherited both traditions – the sense of English as the language of daily life and the language of rhetoricians before it was reined in by the grammarians.

It is true that most of my books come out of my knowledge and experience of the places I have lived in the Midwest. Living in the river town of Cincinnati and interviewing all those rivermen, teaching in East St. Louis, living and studying in St. Louis during the turmoil of the 1960s, and finally living in Auburn, a small town in the heart of Illinois corn and coal country, have all been immensely important to me as a poet.

When I haven't written about where I live, I've written about the wonder and discovery I've felt on journeys that I made. In the 1960s I made trips through the United States from Spearfish Canyon, South Dakota, to Savannah, Georgia, as a consultant for Project Upward Bound. Begging an Amnesty was inspired by several visits to the western United States. Prayer Against Famine, of course, came from three journeys to Ireland and my personal search for relatives there. But that book also includes poems inspired by visits to Alaska, New York City and the Menominee Reservation in Wisconsin. And that book, in kind with almost every book I've written, has references to countries all over the world. Place is important to me.

Regarding comparisons between the past and the present, what you find when you begin paying attention to lost histories is the link that you needed when you began the search in the first place. With the rivermen, I found a language and a sense that the inland rivers and the Midwest itself are worthy subjects for a poet. It has been the same with every story I've told in my poems, I always find some link with that lost past, some link that I needed, though I didn't necessarily know this before I began the poem. Often that discovery becomes the burden of the poem.

In terms of Ireland and America, what I was looking for when I began that book was my Irish family. What I found, in a mass grave in Skibbereen in County Cork, was the famine – An Gorta Mor, the Great Hunger. I began to understand that the events that sent some members of my family to the United States as immigrants and probably put others in that mass grave in Cork are pretty much the same things that we all worry about today: hunger, poverty, injustice, war, the silencing of peoples and their cultures. That was on my first trip to Ireland. And it was what made me include in the book poems about people in many other countries.

In 1998 I was in Derry and Belfast the week after the Good Friday Peace Accords. That was a stunning time. I realized that famine is spiritual as well as physical. And I saw many connections with life in Illinois – including our simmering racial, class and religious tensions, the fear we have of each other. That was just one of the many connections I found between Ireland and America, connections I had not imagined when I began the book. But I still couldn't find my Irish family.

When I finally did locate the home of my Irish cousins, it was not in Ireland but on the Menominee Reservation in northern Wisconsin. So I'd returned full circle, to my own Midwest with no easy answers but a whole universe of relatives – and questions.

My impulse with the book is that someone will find it and read it and say, "Why that must be a cousin wrote this book."

Seen close up, those walls are rough, but the stones are really chinked in there – flat stones, not boulders. They fit together well. They became for me a kind of metaphor for the lines in a poem. You build them as you can.

Learning the history of those walls gave those crooked lines many more meanings than I had imagined when I first saw them. They aren't like the walls in Frost's poem "Good Fences Make Good Neighbors." Especially in the west counties they are testimony to a seaboard culture that goes back generations beyond measure. I like the – for lack of another word – strange privacy that they give, a protection for the fields of farmers that we have lost with our megafarms in the Midwest and our habit of destroying.

The stones are so plentiful, the building skills so persistent, you can't tell sometimes whether a wall was built in neolithic times or just last year. They are signatures of generations.

Some of those walls were built during the famine. They had no function except to make work for the Irish poor so that they would pay at least in labor for any food relief given to them. By the time I finished the book, "thank god for crooked lines so long in making" was carrying a much heavier burden than when I first wrote it down. So that what those walls represent is something held in trust and in a strange way, for myself and other visitors who come back to Ireland for families that they cannot find.

But the more I understand about the Irish landscape, the more it takes me back to Illinois again and our own version of famine and plenty. In my generation we watched tens of thousands of acres of the richest farmland in the world given up to shopping malls, the corn cobs of the last harvest scattered along the edges of parking lots for cars parked at fast food restaurants. The prairie-fed loam here in Illinois goes six feet and more to the clay.

So I'd say at first I felt a sense of wonder at the Irish landscape, and then a sense of discovery that took me back to my own Illinois landscape.

Survival, too, is a subject of this book – the survival of my Irish immigrant family, the birth of my granddaughter, the lines for the miscarried child who will not be forgotten.

Cultural survival, again something I could not have imagined when I began this book, became one of its subjects: the festival of traditional singing in County Clare, the dance of the Inipiut, the Menominee's successful struggle to preserve the ancestral deep woods – and the knowledge they shared, at great price, with the U'wa of Colombia.

I wrote about my search for my family in Ireland, and these turned out to be the themes I found.