Who is Edward Steichen from On Photography and what is their importance?

Edward Steichen (1879-1973) was an American photographer, artist, and gallery curator. He was born in Luxembourg and became an American citizen in 1900. With Alfred Stieglitz, Steichen created the Little Gallery of the Photo-Secession. He took extensive photographs of military operations in World War I and, later, moved into fashion photography. During World War II, he again returned to military operations photography. In 1955, he created The Family of Man, an exhibition at the Museum of Modern Art, featuring photographs from dozens of countries. The text refers to Steichen's work often, though usually without much comment beyond offering his work as an example of the topic being discussed.