Exploitation of German language sources in Civil War scholarship has largely been a recent phenomenon, and Keller's examination of the ethnic German soldiers that fought with the Union Eleventh Corps is one of the most illuminating studies to emerge from it. While others have argued that the war advanced German assimilation into American society, Keller offers an alternative view that many have come to accept, that the severity of the nativist backlash against the German soldiers in the wake of the Eleventh Corps's twin routs at Chancellorsville and Gettysburg instead prompted Germans to defensively retain their own separate cultural identity and reject broader assimilation. Support for Keller's thesis is contained in #3 below, as well.2. The Germans of Charleston, Richmond and New Orleans during the Civil War Period, 1850-1870 (2011) by Andrea Mehrländer.
With the vast majority of the literature focusing on northern Germans, Mehrländer's study alternatively looks at the immigrant experience in three major southern cities. Her book is the "is the first monograph which closely examines the role of the German minority in the American South during the Civil War. In a comparative analysis of German civic leaders, businessmen, militia officers and blockade runners in Charleston, New Orleans and Richmond, it reveals a German immigrant population which not only largely supported slavery, but was also heavily involved in fighting the war." German unit roster tables are also included.3. Germans in the Civil War: The Letters They Wrote Home (2006) edited by Walter D. Kamphoefner & Wolfgang Helbich.
The editors add much in the way of supporting text and footnotes to a collection of over 300 letters originally written in German by 78 individuals and addressed to family and friends back in their original Central Europe home lands. An attempt is made to make the selections as representative as possible, with home and military fronts covered and letter writers of both sexes and from both sections included in the book.4. A German Hurrah!: Civil War Letters of Friedrich Bertsch and Wilhelm Stangel, 9th Ohio Infantry (2010) edited by Joseph R. Reinhart.
No short list would be complete without mentioning the prodigious efforts of Kentucky's Joseph Reinhart, who, in addition to translating and editing the above letters from 9th Ohio soldiers, has authored a number of other books highlighting the German-American military experience and contributions to the Union war effort in the western theater with the 6th Kentucky, 32nd Indiana, and 82nd Illinois regiments.5. Abolitionizing Missouri: German Immigrants and Racial Ideology in Nineteenth-Century America (2016) by Kristen Layne Anderson.
Civil War era German immigrants were renowned for embracing the political views of the radical wing of the new Republican Party, but Anderson's study of the Germans of St. Louis reveals much more diverse and evolving attitudes toward slavery and racial equality among the population.