One hundred and fifty years ago General Robert E. Lee surrendered to General Ulysses S. Grant at Appomattox, Virginia, thereby signaling the end of a long and bloody war which had been fought over the question of whether a political state had a right to leave a union it had voluntarily joined. History books enumerate the varied and difficult sociopolitical causes that led to the rupture of the United States and the devastating effects the rupture had on the people and the nation. At the heart of the rupture was a central question, was the United States a federation or a confederation? Modern attempts to clarify the difference between the two types of union focus on a key difference between otherwise similar political institutions – voluntary entry and the notion that a sovereign state that enters voluntarily should in turn be able to freely exit if it chooses. In the nineteenth century, the American Civil War seemed to have determined that the United States had become a federation upon the signing of the U.S. Constitution and the dissolution of the union would not be tolerated. In the twentieth century, other confederations would seek dissolution with varied levels of success. Arguing that they had never agreed to become a federation but had only agreed to a loose confederation, political states like Slovenia managed to declare and achieve independence. Not all attempts by small political states belonging to larger political unions succeeded in achieving both independence and international recognition without first engaging in prolonged civil wars. During the American Civil War and the many civil wars of the twentieth century, the international community, particularly the great powers, felt the need to intervene usually, but not always, on the side which sought to protect the status quo. Interestingly, as important as maintaining the status quo and suppressing war might have been to the great powers, occasionally they would see value in the breakup of large unions regardless of whether the unions were federations, confederations, or empires.  In the end, it seemed to matter little how a union was defined, rather what mattered was how the other great nations could best benefit economically, politically, and socially. In the case of the American Civil War, the great powers decided that intervention would be too costly. Keeping peace in Europe was enough of a problem without throwing support behind a bunch of rebel states wishing to form a separate, more loosely bound union. Prior to April 9, 1865, there had been a debate as to whether the United States was a confederation of states voluntarily joined and with the right to freely exit. With the defeat of the South, the debate should have ended. However, despite the fact that the events at Appomattox Court House comprised a defining moment in U.S. history, the distinction between federation and confederation did not seem to solidify, at least not when secessionist rhetoric finds a foothold.