[1] He formerly served as director of the Institute for Computing in Humanities, Arts, and Social Science (CHASS) and professor of history and sociology at the University of Illinois.

[2] He is also a senior research scientist at the National Center for Supercomputing Applications, where he is associate director for humanities and social sciences.

After service in the Army Reserve he entered graduate school at Princeton University.. His dissertation involved tens of thousands of IBM cards on individuals and farms for a county in South Carolina in the mid 19th century.

He wrote The Age of Lincoln, winner of the 2007 Chicago Tribune Heartland Prize for non-fiction.

[6] He received the American Historical Association’s Eugene Asher Distinguished Teacher Award for 2003.