Duncan was born and raised in a small town in Iowa, then went east for college, graduating from the University of Pennsylvania with a degree in German literature. From there he went to New Hampshire, where he worked for The Keene Sentinel as a reporter, editor and editorial writer. His weekly syndicated humor column, "Wooden Nickels," ran in 17 northern New England newspapers. Articles of his have appeared in the New York Times, the Boston Globe, the Chicago Tribune, the Old Farmer's Almanac, and American Heritage magazine. Owns Highcroft Racing, a top historic racing team; Dayton began his racing career in the vintage ranks. He regularly competes in Historic Sportscar Racing (HSR) vintage events in two cars which he owns: an orange 1972 Chevron B23 and a yellow 1967 Lola T-70 Mk III. Both of them are in group sevenin the HSR classifications. Also owns the car that Mario Andretti drove to the Formula 1 World Championship in 1978. In politics, Duncan served as chief of staff to New Hampshire Governor Hugh Gallen, as national deputy press secretary for Walter Mondale in the presidential campaign of 1984, and as press secretary to Michael Dukakis in the 1988 campaign. He has also been a fellow at Harvard's Shorenstein Center for Press, Politics and Public Policy. In 1998, President Clinton appointed him as chairman of the American Heritage Rivers Advisory Committee; and Secretary of Interior Bruce Babbitt appointed him to the board of directors of the National Parks Foundation. He is the author of seven other books about American history. Out West: An American Journey (Viking Penguin 1987) chronicles his retracing of the Lewis and Clark trail; it was a Book-of-the-Month Club alternate selection and finalist for the Western Writers of America's Spur Award. Grass Roots: One Year in the Life of the New Hampshire Presidential Primary (Viking Penguin 1991) is a unique look at presidential politics through the experiences of grass roots volunteers. Miles From Nowhere: In Search of the American Frontier (Viking Penguin 1993) examines the current conditions, history, and people of the most sparsely settled counties in the United States. Two books for young readers were published by Little, Brown in 1996: People of the West, named a Notable Children's Trade Book for 1996 by the National Council of Social Studies and the Children's Book Council, and The West: An Illustrated History for Children, which was selected by The New Yorker magazine for its "short list" of the 16 best children's books of 1996 and won "The Wrangler" award from the National Cowboy Hall of Fame. Lewis & Clark: The Journey of the Corps of Discovery was published in 1997. Duncan has also been involved for many years with the work of documentary filmmaker Ken Burns. He was a consultant on Burns' award-winning series for public television, The Civil War and Baseball, and was co-writer and consulting producer for a 12-hour series about the history of the American West which won the Erik Barnouw Award from the Organization of American Historians. He wrote and co-produced Lewis and Clark: The Journey of the Corps of Discovery, a 4-hour documentary that attained the second-highest ratings (following The Civil War) in the history of PBS and was the winner of the Spur Award, "The Wrangler," a CINE Golden Eagle, and many other awards. Duncan's next film project with Burns is a biography of Mark Twain.