Ken Burns and Dayton Duncan of Florentine Films have done it again. Already credited with some of the best documentaries of our time: The Civil War , Jazz , The West , Baseball , and most recently, The War , the duo have become the video biographers of the American nation. Their latest film, National Parks: America's Best Idea , is a 12-hour, six-part series premiering this Sunday, September 27 on PBS at 8:00 p.m. (EST). Video Biographers of the American Nation, Co-Producers Ken Bur