Leah Bendavid-Val is director of photography publishing for National Geographic Books. She is the author of five books on photography including Song Without Words.

Michelle Anne Delaney is an associate curator in the Photographic History Collection, National Museum of American History, Smithsonian Institution.

Maura Mulvihill is a vice president and director of the Image Collection at National Geographic, where she has worked for 30 years.

The book takes the reader from the time National Geographic's first editor and president began collecting pictures, until today, with important photography still being created as energetically as ever. Two thoughtful essays introduce the book, giving varying perspectives on the pictures. Then the book is divided into four themes: 'Wilderness, Exploration and Adventure'; 'Wildlife'; 'Peoples, Cultures and Lifestyles'; and 'Science and Climate Change'. Each section's content and images describe the evolution of photography, both technically and aesthetically. A one hundred page Appendix closes the book and serves as a reference to the entire collection. The appendix is divided into three parts: 'The Special Collections'; 'A Complete List of Subjects'; and 'A Complete List of Photographers'. The Appendix will describe the size, range and character of all aspects of the National Geographic Picture Collection and will feature brief biographies of photographers whose work is represented.