Just about every nation in the world, to some extent, admits immigrants. But there's something unique about America. We don't simply welcome new immigrants, we don't simply welcome new arrivals — we are born of immigrants. That is who we are. Immigration is our origin story. And for more than two centuries, it's remained at the core of our national character; it's our oldest tradition. It's who we are. It's part of what makes us exceptional.

Naturalization Ceremony speech (December 2015)