The Commercial and Political Atlas

William Playfair invented the line chart, bar chart, and pie chart — three of the most fundamental visualization forms still in daily use nearly 250 years later. His 1786 Commercial and Political Atlas contained 43 charts tracking England’s trade balances with other nations over time.

The line chart of England’s trade with Denmark and Norway is particularly notable: it uses color-filled areas between import and export lines to show the balance of trade, making surplus and deficit immediately visible. This “area between two lines” technique is still used today.

Playfair’s genius was translating the accountant’s table of numbers into spatial relationships that the eye could grasp instantly. He faced skepticism from contemporaries who trusted only tables, but his visual approach eventually won because it revealed patterns that tables could not.