Progressivism, in its original 19th-century form, was the offspring of pessimism. Part of that pessimism was a revulsion at what the Civil War had done and, more to the point, failed to do. It had taken an America whose driving intellectual forces were enthusiastically religious, artistically naïve, and absolute in their moral self-confidence, and plunged it into a four-year bloodbath led by incompetent generals, pockmarked by genocidal massacres (as at Fort Pillow and the Crater), and frothing with stupidity, greed, and fraud. Overall, approximately one out of every ten white American males of military age in 1860 was dead by 1865 from some war-related cause. Even after the war, the federal government would be paying pensions to nearly one million Union veterans or their dependents, at a total cost (by 1900) of almost 22% of all federal expenditures.
And for what? Emancipation, yes. Union, yes. But the promise that emancipation would produce an egalitarian, biracial society was cruelly smashed by the failures of Reconstruction, and reunion only resulted by the 1880s in a revival of the same old alliance of corrupt Northern Democrats and white-hooded Southern Democrats that had brought the country to the brink of war in the first place. Oliver Wendell Holmes went into the war a Boston Brahmin idealist, convinced that it was “the Christian Crusade of the 19th century.”