A vendor sells seafood at a market in East Broadway in New York City's Chinatown. There was a 17 percent drop in the population of New York City's Chinatown over the past decade, and some say it's a sign that Chinatown is becoming more of a symbolic touchstone. Rebecca Sheir/NPR hide caption

itoggle caption Rebecca Sheir/NPR

American abolitionist John Brown led the 1859 raid on Harpers Ferry, Va. That takeover and the man behind it are the subjects of historian Tony Horwitz's new book, Midnight Rising. Hulton Archive/Getty Images hide caption

itoggle caption Hulton Archive/Getty Images

President Calvin Coolidge (right) with the national Christmas tree on Dec. 24, 1923. National Photo Company/Library of Congress hide caption

itoggle caption National Photo Company/Library of Congress

In February 1945, Hershel Williams was sent to Iwo Jima with a flamethrower unit. A week and a half later, all but 17 of the 279 members of his company had been killed or wounded. Nick Del Calzo/Courtesy Artisan Books hide caption

itoggle caption Nick Del Calzo/Courtesy Artisan Books

As a dissident playwright, Vaclav Havel led the Velvet Revolution to bring down Czechoslovakia's communist regime in 1989. AP hide caption

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Musicians perform at the inaugural ceremony of the International Center for the Study of Machu Picchu and Inca Culture — a partnership between Yale University and The National University of San Antonio Abad in Cuzco. Tim Moran hide caption

itoggle caption Tim Moran