This stuck with me: "In the end, the American dream is not a sprint, or even a marathon, but a relay. Our families don't always cross the finish line in the span of one generation. But each generation passes on to the next the fruits of their labor. My grandmother never owned a house. She cleaned other people's houses so she could afford to rent her own. But she saw her daughter become the first in her family to graduate from college. And my mother fought hard for civil rights so that instead of a mop, I could hold this microphone."
Full text of speech, here.