Some historians argue that the U.S. Civil War was the single most important event in shaping our country. It defined us as a nation and brought us together as single country.

Before the war, it was common to view oneself as a citizen of a particular state, and then as a citizen of the United States. The country was made up of deeply divided sectional views. After the war, we saw the value of one nation with one government of the people, by the people and for the people. Before the war, the prevailing view was that states and state laws were of greater importance than the federal government. After the war, the federal government became predominant. Before the war, we were a nation of cottage industries. After the war, federal laws and regulations helped us build the transportation and communication networks needed to build a nation of industry. Finally, the war resulted in the 13th, 14th and 15th Amendments to our Constitution, abolishing slavery, introducing the due process of law, and guaranteed the right to vote to all men born in the U.S., thus starting the social and political changes that we continue today.

At 4:30AM, 12 April 1861, Confederate forces began their bombardment of Fort Sumter in Charleston harbor, South Carolina, starting the U.S. Civil War. The war was fought over slavery, but it didn't start as a war to free the slaves. That paradox is a source of confusion about the cause of the war. Gradual westward expansion threatened to tip the balance of power and control of the federal government either toward the South or the North, and a series of compromises were constructed to alleviate that tension from 1820, right up to the outbreak of war. The centerpiece of Republican Party platform in 1856 and 1860 was not emancipation, but "non-extension," a policy that would prohibit slavery in the territories and halt the introduction of new slave states into the union. Non-extension wasn't about abolishing slavery, but containing it.

The Emancipation Proclamation, the executive order issued 1 January 1863, freeing slaves held in rebel states, transformed the war's purpose from non-extensionism to abolitionism. Military necessity prompted Lincoln to issue it, but the moral reframing inferred in it changed the course of the war and its eventual settlement. Lincoln called for a "new birth of freedom", essentially criticizing the contradiction between the promise of liberty found in the Declaration of Independence and the original Constitution's position on racial inequality. The need for the Emancipation Proclamation showed that the union could no longer be preserved as it had been, but had to be reconstructed. The three Constitutional Amendments proposed and ratified shortly after the war constituted that new basis. Those three Amendments did more than simply revise the original Constitution, they transformed it. Not since the original Constitution was ratified had so many amendments been proposed and ratified in succession. They redefined the phrase "We the People" by drawing freed slaves into the definition of American citizenship and reordered the relationship between the states and the federal government.

The resulting Constitution of 1870 was one that clearly stated national primacy, with a derivative state citizenship and a greatly expanded role for the federal government and federal courts to protect our rights of citizenship from state interference. Most importantly, they did more than protect freedman from discrimination or state imposed disabilities; they were an affirmative vision of a new American political community.

American slavery and racial caste were not separate systems, but mutually conceived and part of a common belief system for many Anglo-Saxons . The Radical Republicans sought not merely to free slaves and make them citizens, but to remake society and effect a social transformation. This was to be accomplished through a program that secured citizenship and empowered freedmen with rights to land, education, and the right to vote. They saw this as the moment in history to rewrite the rules of the game. To that end, they rebuilt Constitutional law to insulate their effort from subsequent reversal by the Courts or the Congress upon the readmission of southern states. Their success was only partial and temporary. The economic panic of 1873 shifted public opinion away from Reconstruction and the Tilden-Hayes Compromise formally concluded it with the withdrawal of federal troops from southern states.

Over the next thirty years, the Supreme Court systematically overturned much of their work through a series of decisions narrowly interpreting the Reconstruction Amendments: The Slaughterhouse Cases of 1873, The Civil Rights Cases of 1883, and Plessy v. Ferguson of 1896. Only one of those cases has since been overturned. The Civil Rights Movement in the mid-20th century is largely responsible for restoring much of that Reconstruction vision, but in many ways the resolution of the Civil War (including the meaning and scope of the Reconstruction Amendments) remains deeply contested today. Many of our current civil rights struggles are the legacy of the battles won and lost in the Reconstruction and post-Reconstruction eras.