GETTYSBURG (Reuters) - The U.S. National Park Service began removing Confederate flag merchandise from its bookstores and gift shops on Thursday, joining a nationwide push by lawmakers and retailers to remove the emblem, long associated with the fight to preserve slavery. Kathy Kupper, a national parks spokeswoman, said she doesn't know how many parks had previously sold Confederate flag merchandise, but about 70 of the organization's 407 parks are related to the American Civil War. “We strive to tell the complete story of America,” National Park Service Director Jonathan B. Jarvis said in a press release. “Any stand-alone depictions of...