Book Review: Green and Blue: Irish Americans in the Union Military, 1861-1865

Green and Blue: Irish Americans in the Union Military, 1861-1865. By Damian Shiels. Baton Rouge: Louisiana State University Press, 2025. Hardcover, 318 pp., $50.00.

Reviewed by Tim Talbott

For better or worse, popular culture has influenced our perceptions of Union Irish American soldiers during the Civil War. Whether it is the insightful and wise Sgt. Buster Kilrain of Killers Angels book and Gettysburg motion-picture fame or the rough and stern dill master Sgt. Maj. Mulcahy in Glory, these brief glimpses clearly leave us with incomplete understandings of the Irish American experience during the Civil War. In doing so, such popular culture images can foster a myth-based view of the “Sons of Erin” and their important role in America’s defining event.

Previous scholarship on Irish Americans include in-depth regimental and brigade works, as well as letters collections and memoirs from soldiers at all ranks of military service. Broader studies like Susannah J. Urals’ The Harp and the Eagle: Irish-American Volunteers and the Union Army, 1861-1865 (New York University Press, 2006), along with more nuanced examinations like Richard G. Samito’s Becoming American Under Fire: Irish Americans, African Americans, and the Politics of Citizenship during the Civil War (Cornell University Press, 2009) have expanded our understanding of the complexity in Irish American social, political, and economic motivations for fighting. Making a significant contribution to this solid foundation of scholarship is Green and Blue: Irish Americans in the Union Military, 1861-1865 by Damian Shiels.

With Blue and Green, Shiels explains, “the book’s ultimate goal is to provide the most detailed understanding yet possible of Irish Americans who served in Union blue during the American Civil War: who they were, where they came from, what shaped them, what they experienced, and what some of them thought.” (3) In order to accomplish this ambitious goal, Sheils takes a different methodological approach than previous scholars. As he states, “A central component of this book is analysis of the lives and correspondence of 395 Irish American soldiers and sailors drawn from across the full breadth of Union arms.” (9) This amazing treasure trove of documentation came “through the systematic analysis of approximately 168,000 chronologically arranged pension files that were reviewed over an eight-year period.” The result is that “these men are the most fully representative group of Irish American service men ever gathered together for analysis.” (9)

Additionally and amazingly, within those selected digitized pension files, Shiels discovered “1,135 letters composed by or for these 395 Irish American servicemen.” To supplement these first-hand accounts, 297 more pieces of correspondence connected to these individuals were located. As Sheils states, “This represents the most important corpus of ordinary Irish American wartime writing yet gathered together.” (9-10) Obviously, to claim that Shiels research efforts are impressive is a vast understatement.

Following an informative introduction that provides a good historiography on the subject, as well as the information in the two previous paragraphs above, Shiels offers readers five chapters of analysis and interpretation.

Chapter One examines “The Union Irish on the Eve of the Civil War.” In it, Shiels explains that “what sources such as the pension files make plain is that a thorough understanding of these men’s economic background and circumstance is essential to considerations of what shaped them and the decisions they made between 1861 and 1865.” (20). He also reminds us that those who identified as Irish American extended far beyond those individuals who were recorded in the census records as being born in Ireland.

Chapter Two, “In Search of the Irish American Serviceman, 1861-1865,” provides a wealth of information in text, as well as graphs, tables, and maps explaining where these men came from and in what numbers. Sheils argues that the traditional thought that about 150,000 Irish Americans served the Union cause is too low. His analysis suggests a figure more in the line of 250,000.

Chapter 3, “Life in Uniform” gets into subjects that students of the so-called “common soldier” will thoroughly enjoy. Drawing heavily from the letters found in the pension files, Shiels examines topics like “Adapting to Military Life,” “Faith,” “Interactions with Home and Family,” and “Staying in Touch: Newspapers and Letters.” Chapter Four, “Reputation, Race, and Politics” similarly continues exploring topics like “Irish American Manhood and Masculinity,” “Alcohol,” “Desertion,” “Nativism,” “Race,” and “Irish American Politics.”

Chapters Thee and Four shatter myths too often assigned to Irish American Union soldiers and provides fascinating reading. Of Irish American soldiers, Shiels states, “They were less wild, less violent, and less drunk—in essence less different—than they were often given credit for.” (133) Another important point that Shiels makes is that although much of the previous focus on Irish Americans have come from spotlight studies on Irish American regiments and brigades, that Irish American individuals were also heavily sprinkled throughout Union units of all kinds and from many regions, too, and should not be avoided. Shiels’ method of research ensures they are not forgotten.

In Chapter 5, “Identity and Motivations,” Shiels argues that understanding these subjects “first requires an analysis of how these soldiers and sailors viewed themselves, viewed Ireland, and viewed the United States.” Doing so allows us to understand that “these aspects of identity are integral to understanding how they perceived their military service, enabling in turn a fuller comprehension of why so many enlisted.” (135) Here, Shiels examines “’Irish’ Identity in Uniform,” “’American’ Identity in Uniform,” “The Place of Ireland in Irish Identity,” and “Motivations for Service.” Shiels ends the chapter explaining that “many of the 250,000 ethnic Irish who fought for the United States did so in the belief that they were fighting for their country—every bit as much as their native comrades who touched elbows with them on the battlefield. (171).

A short conclusion is followed by an appendix that provides brief biographies about many of the men who receive mention within the text. Over 80 pages of notes, bibliography, and a helpful index end the study.

Due largely to its depth of research, and the analysis of the new source material Shiels uncovered, Green and Blue: Irish Americans in the Union Military, 1861-1865, is sure to be the go to source on Irish American soldiers for decades to come. It will also hopefully serve as a potential model for future studies on other ethnic groups that served the Union in large numbers.