One Nation Divsible is a study of demographics in the United State since 1900 based on the U.S. Census written by Michael B. Katz, an historian at the University of Pennsylvania. The project required graphs from tabular data that could be printed only in one color. A large percentage of the data dealt with comparisons of gender and ethnicity, so it appeared reasonable to develop an intuitive vocabulary where possible. These two graph fragments show some of those techniques: the use of the Mars symbol and a solid line for men, and the Venus symbol and dashed lines for women, respective. A light gray background permits white lines/bars of whites, black lines/bars for African Americans, and dark gray lines/bars for other ethnicities (in this case, Mexican Americans).
