John R. Neill (1877-1943)
best known for: the Oz series
Most of the books illustrated by Neill are actually “chapter books” and not picture books but some are so heavily illustrated as to feel like picture books. Neill is most famous for illustrating the Oz books created by L. Frank Baum. He actually illustrated a whopping 35 of them over over four decades. His work is exquisite and has a strong turn-of-the-century feel. The women look like Greek goddesses with long, delicate features and flowing robes.
Neill also illustrated non-Oz fantasy books by Baum, worked extensively for periodicals, and even had a couple of his own comic strips (Nip and Tuck and Toyland). However, he is best known by far for his Oz work, creating the visual designs for iconic characters like Jack Pumpkinhead, Ozma, the Nome King, Patchwork Girl, and many others.