The Civil War and Reconstruction Era, 1845-1877 (audio version) by Professor David Blight (Yale)
The course is available at iTunes University - 27 podcasts, running about 50 minutes each. This is the course descpription from the site:
(HIST 119) This course explores the causes, course, and consequences of the American Civil War, from the 1840s to 1877. The primary goal of the course is to understand the multiple meanings of a transforming event in American history. Those meanings may be defined in many ways: national, sectional, racial, constitutional, individual, social, intellectual, or moral. Four broad themes are closely examined: the crisis of union and disunion in an expanding republic; slavery, race, and emancipation as national problem, personal experience, and social process; the experience of modern, total war for individuals and society; and the political and social challenges of Reconstruction. This course was recorded in Spring 2008.