How does the Amendment process show the dynamic nature of the Constitution?

US constitutional amendment process

The Congress, whenever two thirds of both houses shall deem it necessary, shall propose amendments to this Constitution, or, on the application of the legislatures of two thirds of the several states, shall call a convention for proposing amendments, which, in either case, shall be valid to all intents and purposes

lincoln declared that slavery should not be allowed to spread into the new states, and of course this angered the south at the time.