I don't believe it could have, as in 1945 the Lost Cause narrative had yet to be fully recognized, questioned, or rejected. In 1945, the Dunning School still held sway, as it would until the 1960s. Historians largely viewed the South as, if not necessarily justified in seceding, then certainly not in the moral wrong. The impact of the slavery issue was minimized in favor of an emphasis on constitutional disagreement and regional power struggle. Many books published during this period, as in the case of Douglas Southall Freeman's magisterial works on Lee and the Army of Northern Virginia, focused on the small war. They concerned themselves with generals, their strategy and tactics, campaigns, battles, high politics, and the like, while effectively glossing over the sordid bits and ignoring the broader picture. Reconstruction in particular throughout this period was viewed as a colossal failure, not because it failed to secure the rights of freed blacks (which Howard Beale called "claptrap"), but because it tyrannized, oppressed, corrupted, and degraded the South to the benefit of northern industrialists.

This view of the war - one in which North and South were effectively neutral in 1860, and the North was decidedly bad from 1865-1877 - would not really begin undergoing serious revision until the 1960s. A new wave of historians, including Kenneth M. Stampp and James M. McPherson, influenced by the Civil Rights Movement, shifted the focus away from the generals, battles, and presidents, and back to slavery and black people. For them, slavery was not an incidental; to say so was absurd, and required willful oversight or a focus so narrow as to miss the previous 50 years of American history. Slavery was the issue upon which the country split, and blacks were the critical element in the Civil War. By effectively allying themselves with the Union, by serving the war effort as soldiers, laborers, runaways, and resisters to Confederate authority, they helped to swing the balance, and northerners recognized this at the time.

It's a curious thing that the issue - and the people - whom most historians now recognize as having been at the center of the War, were written out of the narrative for 100 years afterwards. Edward Blum argues that this was intentional and deliberate. In the immediate aftermath of the War, an idea of citizenship based on loyalty had developed and held sway. Blacks, having proved themselves loyal to the Union, were to be favored above supposedly treasonous Rebels, who many viewed as having effectively surrendered their place in the American republic. But as the War faded into memory, and Reconstruction dragged on, accompanied by stubborn white resistance, both legal and illegal, northern enthusiasm for blacks waned. Securing rights to the freemen and reforming the white supremacist South became less important to northern whites than reestablishing a republic built around whiteness. Slavery, and the blacks, had to be written out of the narrative in order to do that. What we got was a picture-book war, full of glory and valor, desperate charges and stubborn defenses, and, above all, stoic sacrifice in the defense of noble ideals on both sides. This is the foundation on which North-South reconciliation was built, and it is the rock on which the rights of the freedmen were broken.

Blum, Edward. Reforging the White Republic.

Lemann, Nicholas. Redemption: the Last Battle of the Civil War.

McPherson, James M. Battle Cry of Freedom.

Edit: fleshed out second and third paragraphs.

The American program of denazification largely grew out of US-based sociology departments and had little to do with perceptions of American history. Instead, it was perceptions of German history, often written by German exiles, that proved to be one of the animating forces behind the shape of the US's denazification program. The Third Reich's hounding out of many intellectuals meant there was a large and very public group of emigres that wrote about the "German problem" during the war and groups like the American Friends of German Freedom gave them a visible platform.

One of the more influential texts upon the architects of the Amzone's denazification was the German emigre and political scientist Franz Neumann's book Behemoth. Neumann argued that the various power blocs within Germany like heavy industry or Prussian militarism enabled Hitler's dictatorship. Behemoth would further contend purging out these individuals from the new Germany would be the ideal way to break up these power blocs. Werner Richter, another emigre and former undersecretary of the Prussian ministry of education in the Weimar Republic, wrote in his 1945 book Re-Educating Germany that the denazification process would need to be led by Germans themselves. Other social scientists and psychologists like Kurt Lewin weighed in on the matter and argued that denazification would need to be a scientific and organized process as a means to educate and inculcate a democratic ethos within Germany. These emigres exerted a great deal of influence upon American planners like Talcott Parsons and Richard Brickner.

The resulting JCS 1067 of April 1945 outlined that denazification was to be a thorough process that would break the social base of authoritarianism within Germany. John H. Herz, a political scientist and emigre, pushed for the denazification process to be a staged process, first with special American groups leading a preliminary process which included questionnaires (Fragebogen ) followed by German-led tribunals (Spruchkammer) defining Germans into five categories (Major Offenders, Offenders, Lesser Offenders, Fellow Travelers, and Exonerated Persons). The denazification process would gradually relax once the major offenders had been winnowed out and lesser offenders could appeal their status.

Although the American efforts at denazification were more ambitious and structured than other zones, they were just as short-lived as their contemporaries and denazification in the Amzone often fell victim to its own ambitiousness. Many Germans did not quite understand the Fragebogen and the military government had great difficulty in sorting out the data. The local American field officers often lacked working knowledge of the areas they were administering, which sometimes meant they appointed German intermediaries that were unsuitable to conduct a denazification campaign. The administration of the Spruchkammer were quite chaotic and their caseloads were too much for the system to bear. Many Germans felt that corruption was rife in these tribunals and this criticism was not entirely unwarranted. Many mid-level NSDAP officials were able to plea their status downwards by sympathetic tribunals or during appeals and the phrase Persilscheine, meaning washing the brown out (Persil was a popular laundry detergent, entered into the occupation vernacular for a disingenuous denazification.

The sheer scale of denazification coupled with the desire to get the Western zone functional also soured many American leaders such as Lucius Clay, the military governor of the American zone, about committing to a thorough denazification. Although the OMGUS authorities pursued a rigorous policy for the first year of occupation, intensive denazification efforts gradually tapered off after 1946. Clay believed that JCS 1067 was fundamentally unworkable and worked to actively subvert it during his tenure as military governor.

There was one interesting area where the experience of the American Civil War popped up in the debates about Germany's post-Hitler future. A number of German intellectuals and politicians postwar would valorize the efforts of exiled German 1848ers in the cause of to preserve the American union and fight slavery. The historian and cofounder of the liberal Freie Demokratische Partei (FDP) Theodor Heuss contended in his book 1848: Werk und Erbe that there existed a fundamental democratic character to the German revolutionaries, one that directly benefited the United States. Heuss argued that the 700,000 German emigres that fled to the United States from 1849-1855 was "for American democracy an immediate gain for the United States." Such an assertion suggests that the existence of a true democratic spirit among Germans in spite of the dark path Germany took during the century after 1848.The lesson of this approach for Germany in 1948 was that Germany’s natural democratic tendencies could reach fruition now that these external conditions that hindered democracy had been removed. Other German intellectuals during the centennial celebrations of 1848 would also highlight that the immigration of these democratically-minded individuals infused the US with a strong spirit of democracy and would aid the US during its struggle with the Confederacy.

Sources

Boehling, Rebecca L. A Question of Priorities: Democratic Reforms and Economic Recovery in Postwar Germany : Frankfurt, Munich, and Stuttgart Under U.S. Occupation, 1945-1949. Providence, R.I.: Berghahn Books, 1996.

Merritt, Richard L. Democracy Imposed: U.S. Occupation Policy and the German Public, 1945-1949. New Haven: Yale University Press, 1995.

Olick, Jeffrey K. In the House of the Hangman: The Agonies of German Defeat, 1943-1949. Chicago: University of Chicago Press, 2005.