A chronographer was a graphical representation of historical information devised by American educator Emma Willard in the mid-19th century. The chronographers intended to show historical information in a geographic and chronological context. The first graphic was Picture of Nations, published in 1835, which showed civilizations as streams running through time, becoming wider and narrower as they gained or lost influence. She developed another chronographer, the Chronographer of American History, in 1844, showing the history of the United States as events marked on the branches of a tree.