“When the National Portrait Gallery reopens next July after a six-year, $216-million renovation, the new space will represent a triumph for preservationists, for artists, for historians — and for Robert Mills. Mills, the original architect, was taken off the project after a rival designer convinced Congress that Mills’ plan in 1836 for a fireproof building — a major preoccupation for a city in which the British had burned the White House 22 years earlier — would not work… Now restorers have peeled away 169 years of history and found that Mills was right.”