Song of Myself was included in Walt Whitman's major work, Leaves of Grass. Whitman paid for the publication of the first edition himself. Three Lions/Getty Images hide caption

itoggle caption Three Lions/Getty Images

Lange's "Migrant Mother" is one of her most famous photographs. Dorothea Lange/Courtesy of the Library of Congress hide caption

itoggle caption Dorothea Lange/Courtesy of the Library of Congress

Before he became the 26th president, Theodore Roosevelt (center) led the men of the 1st Cavalry Volunteers, known as the "Rough Riders," on San Juan Hill during the Spanish-American War in 1898. William Dinwiddie/Hulton Archive/Getty Archive hide caption

itoggle caption William Dinwiddie/Hulton Archive/Getty Archive

Sarah Silverman won an Emmy in 2008 for her video I'm F******* Matt Damon, which appeared on the Jimmy Kimmel Live show. Steve Agee hide caption

itoggle caption Steve Agee

Though people can become more forgetful in middle age, research suggests that they're at the top of their game in other areas, such as vocabulary and reasoning. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Clarke says he would like to see a separate government Internet network that would be constantly monitored for signs of attack. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Actor Michael J. Fox has written a new book aimed at graduates called A Funny Thing Happened on the Way to the Future. Bryan Adams hide caption

itoggle caption Bryan Adams

An archive photo of Bellevue Hospital, the home of the tiny Bellevue Literary Press, which published Paul Harding's Tinkers. Courtesy of Bellevue Hospital Center Archives hide caption

itoggle caption Courtesy of Bellevue Hospital Center Archives