This is a fantastic book! Originally published in 1978 it is long out of print, but available used (and pretty cheap!) on Amazon and Alibris. I was fortunate enough to find my copy at a used book store in 2001 - it was a library discard! I think this was the very first book exclusively dedicated to the subject of American fashion designers. What's really great about this book are the numerous intimate black-&-white photos, most of which capture the designers out of their studios and at home with family and friends. There are the usual suspects - Ralph Lauren, Calvin Klein, Geoffrey Beene, Diane Von Furstenberg, Halston, Bill Blass, Oscar de le Renta - as well as designers who I had personally never heard of before reading this book.
Stephen Burrows having lots of fun at a sewing machine.
Creepy photo of Rudi Gernreich with a mannequin leg.
Holly Harp draping a new design.
Kasper striking a pose with a dress form.
Halston and 1970s model.
Edith Head hard at work sketching.
Calvin Klein, looking very cool here.