With more than half a million dead in just four years, the Civil War was America's bloodiest conflict and the first to be extensively documented through photography.

From adventurer to author to activist, John Griffith London led a dramatic life in keeping with his celebrated novels like "White Fang" and "The Call of the Wild."

Jack London became so enamored with a dog he met while prospecting for gold in the Yukon Territory that he used their bond to create one of the 20th century's most iconic works of literature.

A surprising new discovery of ancient human remains in Africa — with remarkably well-preserved DNA — is redrawing the map of human populations in new and exciting ways.