The most obvious constitutional result of the Civil War was the adoption of three landmark constitutional amendments. The 13th ended slavery forever in the United States, while the 14th made all persons born in the United States (including the former slaves) citizens of the nation and prohibited the states from denying anyone the privileges and immunities of American citizenship, due process or law, or equal protection of the law. Finally, the 15th Amendment, ratified in 1870, prohibited the states from denying the franchise to anyone based on "race, color, or previous condition of servitude."
These amendments, however, have their roots in the war itself, and in some ways can been seen as formal acknowledgments of the way the war altered the Constitution. Other changes came about without any amendments. Thus, the war altered the Constitution in a variety of ways. A review of some of them underscores how the Union that President Lincoln preserved was fundamentally different — and better — than the Union he inherited when he became president.
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In short, nullification and secession were not new ideas in 1861, when 11 states left the union, but had been part of the warp and weft of constitutional debate since the founding. But the Civil War ended the discussion. The question of the constitutionality of nullification or secession was permanently settled by the "legal case" of Lee v. Grant, decided at Appomattox Court House in April 1865. Grant had successfully defended the Constitution and the idea of a perpetual Union. Secession lost, and the United States won. The Supreme Court would weigh in on this in Texas v. White (1869), holding that secession had never been legal and that the state governments in the Confederacy lacked any legal authority.
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Today we rightly look back at these two amendments, and the 13th, as the most important lasting constitutional legacies of the Civil War. And that they are. But it is also important that we look at how America's understanding of the Constitution, especially as it related to racial and ethnic equality, changed during the course of the war, and not simply as a consequence of it. Put differently: The Civil War amendments changed the Constitution. But even if, somehow, they had never happened, the war itself would have altered the way Americans saw one another, and their government.
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Bringing the