Jim Powell is a senior fellow at the Cato Institute in Washington DC and is an expert in the history of liberty. He has lectured in England, Germany, Japan, Argentina and Brazil as well as at Harvard, Stanford and other universities across the United States. He has written for the New York Times, Wall Street Journal, Esquire, Audacity/American Heritage and other publications. He is the author of several books, including The Triumph of Liberty, A 2,000 Year History Told Through The Lives Of Freedom's Greatest Champions (Free Press, 2000). His most recent book is Greatest Emancipations: How the West Abolished Slavery (2008).