The amendments do not change the nature of the Constitution as an entity, because Article Five is very explicit that when you have an amendment, that amendment is part of this Constitution when ratified by the legislatures of three fourths of the several states. That said, even though the Constitution is not a new kind of entity when we have something like the 14th Amendment, there is a change in emphasis about the purposes of the Constitution. Now what are the purposes of the Constitution? Well, we know those from the Preamble: "We the people of the United States, in order to form a more perfect union, establish justice, ensure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity do ordain and establish this Constitution for the United States of America." The 14th Amendment puts a much bigger emphasis in the entire purpose of the Constitution on securing the blessings of liberty to a broader set of people. It's among the purposes in the preamble at the original Constitution. The three most important amendments changing the text of the Constitution are the 13th, 14th, and 15th Amendments. If you look at the 13th, 14th and 15th Amendments, what they do is they take the freedman up one level in the status hierarchy. So the original Constitution actually refers to them in all three of the provisions protecting slavery as persons. So it's not right to say enslaved persons were not treated as persons Article 1, Section 2, Clause 3, Article 1, Section 9, Clause 1, and Article 4, Section 2, Clause 3, all referred to enslaved persons with that word “persons.” But we go from persons to free persons. It's possible to not be a free person under the original Constitution, but under the 13th Amendment, all of those persons have to be free. So we go from enslaved person to free person by the 13th Amendment. The 14th Amendment then takes people from the status of free persons to the status of citizens. So the freedmen are not to be given merely the rights given to citizens of some other country, they can't be prohibited for instance from owning land, they have to be citizens. Then the 15th Amendment takes the freedman from the status of citizens that the government has to treat properly to voters or electors, people who have to have a share in the decision-making processes of the government itself. So the 13th Amendment takes us from enslavement to freedom, the 14th Amendment takes us from mere freedom to citizenship, and the 15th Amendment takes us from citizenship to participation in the political process.