William Playfair — a businessman, engineer and economics writer from Scotland — created the first known pie chart in 1801. Seeking to illustrate the Turkish Empire’s landholdings for his statistical breviary on the European nation-states, Playfair sliced a circle into three wedges whose sizes were determined by land area. According to a paper called “No Humble Pie: The Origins and Usage of a Statistical Chart” by Ian Spence, professor of psychology at the University of Toronto, Asia’s wedge was the largest and colored green, to indicate that it was a maritime power. Europe was made red to indicate it was a “land power.” It’s not clear why Playfair made Africa yellow, or what inspired him to make a circle graph at all. But, Spence writes, it was “the first pie chart to display empirical proportions and to differentiate the component parts by color.”
