The Judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by Citizens of another State, or by Citizens or Subjects of any Foreign State.
Nice and concise. The Supreme Court had ruled in such a way as to limit the sovereign immunity of the States. (Federal encroachment began early) The Congress passed an Amendment over turning the decision, and the people ratified it. It is notable to us for several reasons.
First, it explicitly limits the power of the Judicial Branch. Second it is an example of the Congress and people of the United States telling the courts that they got it wrong. Far too often we see the Supreme Court as the last, or supreme, authority on what the Constitution means or what the powers of the government are. Third, it is an example of the Congress and people explicitly protecting the power and most importantly, sovereignty, of the States. The States weren't just lines on a map. The United States was much more of a "European Union" type of entity at the time.
There was a follow up case to Chisholm in 1999 called Alden v. Maine, in which four Justices actually argued that the States gave up their sovereignty when they entered the Union.
So, in 1795, (less than seven years after the Constitution was ratified) Congress and the American people both agreed that the States did have sovereignty and yet in 1999, (over two hundred years later) four Justices not only disagreed, they also decided that they knew better than the generation who actually wrote the Constitution. I'll let you guess which wing of the Court sought to weaken the States.