The trust, a private group that advocates for maintaining America's heritage buildings, decided to get involved in Philadelphia after Mayor Kenney asked for its help, said president Stephanie Meeks. Like many cities, she explained, Philadelphia has policies that often make it easier to demolish older buildings than reuse them. "We're going to look at ways the city can unlock the economic potential of its historic buildings," she said. "Philadelphia is one of the country's most historic cities."