On the eve of the American Civil War, 1.6 million Irish-born people were living in the United States. The majority had emigrated to the major industrialised cities of the North; New York alone was home to more than 200,000 Irish, one in four of the total population. As a result, thousands of Irish emigrants fought for the Union between 1861 and 1865.

The research for this book has its origins in the widows and dependent pension records of that conflict, which often included not only letters and private correspondence between family members, but unparalleled accounts of their lives in both Ireland and America. The treasure trove of material made available comes, however, at a cost. In every instance, the file only exists due to the death of a soldier or sailor.

From that as its starting point, coloured by sadness, the author has crafted the stories of thirty-five Irish families whose lives were emblematic of the nature of the Irish nineteenth-century emigrant experience.