The Thirteen Colonies in their War of Independence had fought for freedom. But the French Revolution (a true revolution of an underclass) proclaimed not only liberty but equality: and that idea was loosened on the world. But liberty (freedom) and equality are natural allies only up to a point, and then enemies. They were opposed to a degree imperfectly understood by either side in the War for Southern Independence. Which principle was henceforth to limit the other? That question was at issue.
The North, fighting for a compelled union, won; but what also won was ever broadening equality, limiting freedom. More immediately what won was—America. Henceforth Virginians and Carolinians were to be Americans and even, with a grim irony, Yankees. The “United States” ceased to be a plural term: a nation supplanted the united nations. Even the word “Union” disappeared, for the ghost of the old, dead, voluntary union of states clung about it and made it un-American. The Negro also won the war, almost incidentally, for the North did not fight for him but against his master: it was not a crusade, except for a few; and emancipation, limited to the Confederacy, was an act of war, not humanity. But the great, hidden victory was that of equality: the very words “freedom” and “equality” became confused and virtually synonymous. Now, said Karl Marx in 1866, the United States are “entering the revolutionary phase.”