Our decisions about the data we choose to represent and how we represent it are never neutral. This insightful history traces how data visualization accompanied modern technologies of war, colonialism and the management of social issues of poverty, health and crime. Discussion is based around seventy examples of visualization, from Florence Nightingale's diagrams of causes of mortality in the Crimean War to projects that show the cost of coal and the fate of our rubbish, taking a participatory approach to visualizing cities. This analysis provides a critical framework for understanding the history of information design with directions for contemporary practice.