Consider this from the Earl of Shrewsbury,
"I believe that the dissolution of the Union is inevitable, and that men before me will live to see an aristocracy established in America."
The hard fought victory of the North in 1865 revived the sagging spirits of revolutionaries and progressives in the late 19th century world ranging from John Stuart Mill, to Giuseppe Mazzini, to Karl Marx. As the historian James McPherson pointed out, most of the world in the 1860s looked like the South with a ruling propertied class over a large class of indentured labor. Slavery for most of the rulers of Europe was but a technicality, a legal and semantic distinction. It was the North that was the odd one out. The Emancipation Proclamation turned the war into a fight to end slavery, and dramatically turned public opinion in Britain and France (if not their rulers) to the Union cause.
The United States was once a revolutionary state dedicated to liberty and equality, and was seen as such by so many imperial powers who desired its end. Something to remember as we become just another oligarchic republic with an empire in a long list of so many in world history.
Alexander Gardner, photograph of the recovery of Civil War dead titled The Harvest of Death