The stretch of Fifth Avenue in Shadyside where the Mansions on Fifth sits was once known as Millionaire’s Row, home to families with last names including Westinghouse, Carnegie, Frick and Mellon. Today, many of the opulent structures are gone, but a 20,000-square-foot mansion and a nearby 8,000-square-foot building remain. The
MELLON'S MILLIONS Harvey O'Connor John Day ($3). Few stars have receded into space more swiftly than, in a few months time, the Greatest-Secretary-of-the-Treasury-since-Alexander Hamilton has receded into…