"Downton Abbey" Brings Cool TV Crowd to America's PBS

British World War One-era drama "Downton Abbey" and its colorful cast of countesses, cooks and kitchen maids has taken America by storm, dominating modern social media and bringing millions of new, young viewers to the often staid world of public broadcasting. January's second-season opener on PBS's "Masterpiece" slot drew 4.2 million U.S. viewers -- an 18 percent rise on the first season and rising to 6.3 million in replays and online views.