SECOND-GUESSING the design of the nation’s memorials is as American as the iconic figures they honor. When the Lincoln Memorial was being planned, no less an authority than Frank Lloyd Wright called it the “most ridiculous, most asinine miscarriages of building material that ever happened.” Critics of the Jefferson Memorial wondered why this father of democracy was housed in a Roman temple. So controversial was Maya Lin’s spare homage to those who died in Vietnam that the highest-ranking member of the executive branch to show up for its dedication was the deputy interior secretary....