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,...