This two-volume set is an accessible and attractive read. The handy timeline at the beginning provides the reader with a better understanding of the world at the time of the subject’s contributions. This is especially useful for readers studying figures from before their lifetime who might not comprehend the broader context of the subject’s activities.

Entries are notable figures who contributed in some way to society. Many of the persons discussed changed how we live by advancing technology or medicine or by changing the way we think through education and activism. Profiles include some basic biographical information about the subjects’ personal lives, such as their upbringing and education, but focus primarily on the activities that changed public life and opinion. Controversy surrounding their work is also discussed. For the most part, the authors do an excellent job of explaining how a subject changed 20th-century America. A few entries however have information about the person’s achievements but do not sufficiently explain the transformative nature of those achievements. For example, Jack Nickaus’ achievements are well-documented but his lasting impact on golf is not readily apparent from the information provided.

An advantage of this set is that it covers a variety of figures: authors, economists, scientists, politicians, athletes, philosophers, inventors, magnates, artists, and more. Additionally, the “Contents” section at the beginning of each volume provides a chronological list of all persons in the book so that a reader can immediately tell who is included.

The comprehensive index includes the subjects as well as other figures and events. Looking up World War II lists the biographical entries in the set in addition to other people and issues related to the war. For instance, there is a subheading under WWII for the fitness movement. This could be useful for readers interested in knowing about prominent figures in relation to a particular topic.

The set is worthwhile and informative but many of the figures are better-covered in other thematic biographical encyclopedias. Users seldom inquire about twentieth century persons in general; they more often ask about a specific twentieth century decades or for the biographical backgrounds of people in particular categories, such as noted women, African-Americans or athletes. Subject-specific resources would likely be more comprehensive and include more persons from those categories.

Because much of this information is available in subject-specific biographical encyclopedias, this set would be a welcome addition to smaller reference collections that lack those resources. This would be ideal for public libraries and K–12 schools.