Thanks to PBS, you can now download from iTunes a four-hour definitive biography of Franklin Delano Roosevelt. FDR guided the US through the Great Depression, then World War II, serving as president for an unprecedented four terms. The video podcast run a good four hours, and it's part of a series called American Experience: The Presidents. Other presidents featured in this series include Harry Truman, Lyndon Johnson, Richard Nixon, Jimmy Carter, and Ronald Reagan. You can watch more videos from The American Experience series online by clicking here.