Borrowing a technique from Hollywood, historians at the University of Richmond have created animated maps that chart voting patterns in U.S. presidential elections since 1840. The maps present county-by-county data for every presidential election for which data are available, and show how voting patterns shifted over time.

Edward L. Ayers, a pioneer in the use of digital technology to study history, helped create the project. Mr. Ayers, who is president of the University of Richmond, said he hoped that political pundits and others watching this year’s election will explore the maps to get a better sense of its context. The main take-away point, he said, is that American elections have rarely been clear cut or predictable.

“Pundits did a pretty bad job predicting that Barack Obama would emerge in the recent primary,” said Mr. Ayers. “But this kind of ferment and change and surprise has been a hallmark of American politics” throughout the country’s history. See full coverage of the site in today’s Chronicle article, or watch a video report with highlights.