A family reunion gives way to an unforgettable genealogical quest as relatives reconnect across lines of color, culture, and time, putting the past into urgent conversation with the present.In 1791, Thomas Jefferson hired a Black man to help survey Washington, DC. That man was Benjamin Banneker, an African American mathematician, a writer of almanacs, and one of the greatest astronomers of his generation. Banneker then wrote what would become a famous letter to Jef...