The Roosevelts: An Intimate ­History, a seven-part, 14-hour documentary by celebrated filmmaker Ken Burns, details the interwoven lives of Theodore, Franklin Delano and Eleanor Roosevelt — three American icons from one of the country’s most illustrious political families. Featuring the voices of Meryl Streep (Eleanor), Paul Giamatti ­(Theodore) and Edward Herrmann (FDR), the film examines the unprecedented accomplishments and even the personal flaws of these driven historical figures. PBS will air The Roosevelts: An Intimate History beginning on Sept. 14.