The Encyclopedia of the U.S. Census (2nd ed.) updates and revises its predecessor to reflect the significant changes that have taken place in US census data collection and analysis over the past twelve years. The most notable addition to the encyclopedia is a twenty-two-page section on the American Community Survey (ACS) that covers historical and methodological aspects of this survey, which has replaced the long-form census questionnaire. The ACS section also includes a guide to understanding and using ACS data products, a particularly helpful addition because these products differ substantially from the data products of the modern decennial census.

The remainder of the encyclopedia has been updated to reflect changes in policy and practice since the first edition. Historical articles remain virtually unchanged, although the editors have added some discussion in reference to the ACS. Articles on current topics have been substantially or entirely revised. Some topics briefly mentioned in the first edition are expanded to full articles in the second, while a few tangential articles are contracted to provide more general information. The bibliographies for each entry have been updated with URLs to online resources, and the appendix includes reproductions of the collection forms for the 2010 census and the 2010 ACS. The index has also been improved with the addition of boldface type to indicate full articles. Additionally, this edition has improved its collection of historical photographs and images relating to the census while clarifying the sometimes confusing captioning of the first edition.

Other works about the census and the ACS may provide more directed guidance but are simultaneously focused on a smaller audience. This encyclopedia avoids any significant mention of the mechanics of accessing data through the Census Bureau’s Web interface, an advantage given that the newest data interface, American FactFinder 2, debuted in 2011 and continues to undergo adjustments as new data products are added and browser compatibility improves.

The second edition of the Encyclopedia of the U.S. Census is also notable for its thoughtful treatment of topics including race and ethnicity, undercounted populations, and immigration. A particularly interesting new article entitled “Human Rights and Population Censuses” frankly addresses the role of population censuses in both advancing and hindering human rights within the United States and in the international community.

This work remains indispensable for researchers using data collected and disseminated by the US Bureau of the Census. Students who are using historical census data will find this encyclopedia helpful in providing an understanding of how the data was collected. Genealogists may appreciate the discussion of historical census collection as a basic framework for detailed research into the creation and publication of census schedules, although they will be disappointed in its lack of coverage of the mechanics of accessing and using census schedules. What the Encyclopedia of the U.S. Census does provide is crucial information for librarians providing guidance and instruction in using census and ACS data, along with a fascinating window into the history of the massive undertaking to count and describe the population of the United States.