Mamdani: There is a term so often used to describe our nation and those who have shaped it: American exceptionalism.  American exceptionalism, the conventional wisdom tells us, makes our freedom a little more free, is how we dug the Erie Canal and irrigated the West, is why children in far away lands grow up dreaming of one day moving here. And yet the irony is that the story of America has so often been written by those who were told by others with power and influence and wealth that they were anything but exceptional. For generation after generation, we have been told that when the world has sent its people to our shores, it has not sent its best. It sent Puritans and Sikhs and Quakers and Muslims and Jewish people who were banished for praying the wrong way, worshipping the wrong Gods, angering the wrong people. It sent peasants and serfs from who were treated as less because they hardly owned clothes, let alone land. It sent immigrants for whom power was something someone else had. We are told that America is exceptional because we are richer, stronger, more powerful than everyone else. The truth, my friends, is that America is exceptional because here, nothing is fixed into place. The frontier may be closed, we may have walked on the moon, but the work of fulfilling the values first enshrined in the Declaration of Independence-that work endures, my friends, and it belongs to us all. It belongs too to our newest Americans, those standing here with me today, all of whom were recently naturalized. Nearly a decade ago, I too felt what you feel— the joy of no longer being just a New Yorker, but an American too.