I'm probably not a completely unbiased reviewer of this book -- my dad was born in a sod house in Eastern Colorado in the late 1920's. I heard stories of the Depression and the Dust Bowl all my growing up life on the flat, arid, treeless, barren landscape of the photos in this book. (So you can decide how much you want to trust my assessment of this book.)
This book is fabulous on many levels. First of all, it is inviting and accessible. Every double page spread has a short essay with a telling title and quote that functions as a subheading on the left, and a period photo that illustrates the essay on the right. The photos are so compelling that one way to read the book is simply to look at the photos and read the captions.
As much as it is a book about the Dust Bowl, this is a book about the history of the development of photography as an art form...which just happened to take place during the years of and largely because of the Dust Bowl photographers.
History was changed because of the Dust Bowl and because of the Depression, because of the Okies and because of Roosevelt's response to the economic tragedies of the nation at that time, because of photographers like Dorothea Lange and because of the photographs themselves. At the same time, photography evolved from a portrait-making tool, to a tool for social change. A new form of storytelling, photojournalism, was born of the Dust Bowl and the Depression, as were photographic essays. The way we get information and understand the world around us was radically changed during those years.
Like I said, this book is fabulous on many levels. Pick it up and take a look. I'm pretty sure you'll have a hard time putting it down without reading the whole thing.