U.S. is a large country; it will be more fascinating to explore America's demography. But how can they count the population? What are the features of this nation? How can we research demography?I know that there are whites and blacks. Blacks or Afro-Americans are the minorities in this country. Are blacks the only minorities? I do not think so. I would like to find the answers in my thesis. There are Hispanics, Chinese, Italians, and Russians. There are immigrants and native-Americans. Today in every section of the political, business, and public life we can name people who are members of the U.S. minority. For example Colin Powel, the ex- foreign secretary, is Afro-American. On the movie screen we can observe more people who are minority members. But how many ethnical groups are there in the U.S.? How can we count them? The answer is: Census.