Warner Home Video launches two Civil War tales on Aug. 4: the Richard Gere-Jodie Foster starrer “Sommersby” and mega-miniseries “North & South,” with Patrick Swayze and James Read.“Sommersby” has quietly rung up in excess of $ 47 million at the nation’s box office since its release four months ago, and WHV exex expect the love story to top $ 50 million by the time video is released. For its part, the nine-hour-plus “North & South” averaged a 38 share over six nights for ABC in 1985 and is the “most-requested unreleased video title in the Warner library,” according to a news release. “Sommersby” is a remake of the French film “The Return of Martin Guerre,” and turns on the question of whether a soldier returned from war is really who he says he is. “North & South” is based on the best-seller by John Jakes and produced by David L. Wolper (“Roots,”"The Thorn Birds”). Via one family of Northern industrialists and another of Southern plantation owners, “North & South” chronicles the interlocking fortunes of the two tightly knit families and a nation that is being torn apart.