With Census 2000, users have a special opportunity to study the heritage of America’s population. Summary File (SF) 4 gives users access to extensive detail on the socioeconomic and housing characteristics of the nation’s race, Hispanic, ancestry, and tribal groups. In the past, this file has been large, complex, and expensive. The Census 2000 version is still large, but advances in software, online access, and compression technology have made this file accessible to many new users who did not have access in the past.

All summary files are useful in studying the demographic makeup of the population, but SF 4 is the most detailed Census 2000 file and the only file to offer so many different kinds of data for the broad array of groups in our population.