How do you build a monument to a war that was more tragic than triumphant? Maya Lin was practically a kid when she got the commission to design the Vietnam Veterans Memorial on the National Mall. “The veterans were asking me, ‘What do you think people are going to do when they first come here?’” she remembers. “And I wanted to say, ‘They’re going to cry.’" Her minimalistic granite wall was derided by one vet as a “black gash of shame.” But inscribed with the name of every fallen soldier, it became a sacred place for veterans and their families, and it influenced later designs like the National September 11 Memorial. We’ll visit a replica of the wall that travels to veterans’ parades around the country, and hear from former Secretary of Defense Chuck Hagel about how this singular work of architecture has influenced how we think about war.