The birth of democracy! Okay, I guess I don't know for sure that there weren't other democratic societies before this time, but this is the first you read of it in the Book of Mormon at least. I like the way that Mosiah carefully points out that having a king rule over the land is not bad in itself, it's just that you don't have any guarantee that handing the crown down by rule of succession will result in a string of good kings. And once you have a bad ruler, he/she can drag all the people down too.
With democracy you're not always guaranteed to have the best person leading the country either. People can make bad choices. And of course, not everyone agrees with the choices that are made. If you're in the group whose candidate is not elected, you generally feel that it was a bad choice. But the important thing is that we at least had the opportunity to make our choice. And in a few years down the road, we can make a choice again. In spite of any flaws American democracy may have, we're so lucky to live in a country with this system in place!