Entertainers unveiled for 250th US birthday bash on National Mall

An eclectic mix of entertainers is poised to join a massive bash on the National Mall marking America's 250th birthday that's being billed as a "once-in-a-generation celebration." Country music star Martina McBride, rappers Flo Rida and Vanilla Ice, "Gonna Make You Sweat (Everybody Dance Now)” singers C+C Music Factory and rocker Bret Michaels are among the...