CHICAGO -- Abraham Lincoln has been dead for 142 years, but he still manages to make medical headlines, this time from doctors who say he had a bad case of smallpox when he delivered the Gettysburg Address. Physicians in Baltimore said last week that Lincoln might have survived being shot if today's medical technology had existed in 1865. Last year, University of Minnesota researchers suggested that a genetic nerve disorder rather than the long-speculated Marfan syndrome might have caused his clunky gait. "If you play doctor, it's difficult to shut down the diagnostic process" when reading about historical figures, said...