To what extent did developments between 1860 and 1877 amount to a revolution?
As is often the case with "to what extent" questions, the answer to this is "to some extent." In other words, the developments that happened between 1860 and 1877 were a revolution in some ways, but not in other ways.
The major way in which the events of this era were a revolution is in the area of federalism. Before the Civil War, states had more rights. Most notably, of course, they had the right to decide on whether to have slaves. The Civil War and the Civil War Amendments ended slavery and also forced the states to give up some of their "rights." For example, the 14th Amendment said that the states had to treat all their citizens equally.
However, the events of this time did not really constitute a revolution in terms of the rights of African Americans. Of course, they were freed from slavery and that was a huge change. On the other hand, the end of Recontruction saw blacks returned to a subordinate position both economically and socially. This meant that the end of slavery was not as revolutionary as it might otherwise have been.
The most important change brought about by this time period were the constitutional changes which ended slavery; gave citizenship to Blacks and gave everyone the right to vote. This was accomplished by means of the 13th, 14th and 15th Amendments respectively. By far the greatest change was the passage of the 14th Amendment, whose ratification was made a condition of Southern States receiving full representation in Congress. The Amendment provided that no state would deprive a citizen of the United States of life, liberty or property without due process of law; or deny any citizen of the United States the equal protection of the law. This provision, primarily the Equal Protection Clause, has been construed by the Courts to apply the protections of the Bill of Rights against violations by the states. Additionally, states which uniformly discriminated on the basis of race by a variety of legal methods were enjoined from doing so under the terms of the Amendment.