The census is not the only way to enter into the problems of American diversity, and may not be the best way, but it clearly provides the most authoritative information on the enormous range of races and peoples and ethnicities that make up the American people. It tells us a great deal about their economic situation, their educational progress, the way they are distributed spatially, the degree of their segregation or separation from others, who they marry, and how they conceive their race and ancestry. It is not information that is unaffected by political considerations. The census is directed by an official appointed by the President of the United States – a political appointee – but generally one with some competence in the issues that the census deals with, and his staff is a professionally qualified one. Congress will also get into the act of directing the census. And shaped as it is by politics, the census will also in return shape how Americans see and interpret their diversity. But most important, the census tells us how Americans conceptualize their diversity, and how their views of this diversity and its significance change over time.