Untitled (Kate #18) by Chuck Close. Chuck Close/Courtesy of Pace/MacGill Gallery, New York hide caption

itoggle caption Chuck Close/Courtesy of Pace/MacGill Gallery, New York

Robert Henri's 1913 Figure in Motion was a realistic, but bold response to Matisse's and Duchamp's nudes. Terra Foundation for American Art, Chicago, Ill. hide caption

itoggle caption Terra Foundation for American Art, Chicago, Ill.

J.D. Salinger wrote nine letters and postcards to aspiring Canadian writer Marjorie Sheard. Graham Haber/The Morgan Library & Museum hide caption

itoggle caption Graham Haber/The Morgan Library & Museum

Marville made more than 425 photographs of the narrow streets and crumbling buildings of premodern Paris, including this view from the top of Rue Champlain in 1877-1878. Charles Marville/Musee Carnavalet/Roger-Viollet hide caption

itoggle caption Charles Marville/Musee Carnavalet/Roger-Viollet

Zelda Sayre and F. Scott Fitzgerald pose for a photo at the Sayre home in Montgomery, Ala., in 1919, the year before they married. Bettmann/Corbis hide caption

itoggle caption Bettmann/Corbis

An American soldier reads a letter from home, while taking a break from repairing a tank tread in Lang Vei, Vietnam, in March 1971. David Burnett/Contact Press Images hide caption

itoggle caption David Burnett/Contact Press Images

Carnegie ultimately gave away $60 million to fund a system of 1,689 public libraries across the country. "In bestowing charity the main consideration should be to help those who help themselves," he wrote. AFP/AFP/Getty Images hide caption

itoggle caption AFP/AFP/Getty Images

Nearly 100 years after Edouard Manet painted his scandalous 1863 Olympia, Tom Wesselmann created The Great American Nude #26. Estate of Tom Wesselmann/Licensed by VAGA, New York, NY hide caption

itoggle caption Estate of Tom Wesselmann/Licensed by VAGA, New York, NY

In this 2007 Ellsworth Kelly piece, four separate oil-painted canvases combine to form a single work, Green Blue Black Red. Jerry L. Thompson/Courtesy of Ellsworth Kelly hide caption

itoggle caption Jerry L. Thompson/Courtesy of Ellsworth Kelly