Northern victory in the Civil War was supposed to usher in a new nation. The slaughter of hundreds of thousands on the battlefields did not simply end slavery in America, it also created a new kind of national government designed to promote economic opportunity for everyone.

As Northerners struggled to fight and fund a war of unprecedented magnitude, they replaced a prewar system run by a handful of wealthy Southern slaveholders with a government “of the people, by the people, and for the people.” That new, popular government took firm root in the country after the war, as citizenship was extended and all men got the right to vote. Between 1860 and 1870, it seemed, a Second American Revolution had finally aligned the Constitution with the promise of the Declaration of Independence that all men were created equal.

It didn’t last.