The American artist and naturalist Titian Ramsay Peale II (1799-1885) had a passion for butterflies and throughout his long life he wrote and illustrated The Butterflies of North America: Whence They Come, Where They Go, and What They Do, an ambitious and comprehensive manuscript. The book, along with a companion volume on caterpillars, was never published and resides today in the rare book library of the American Museum of Natural History in New York. Now, Peale's colour plates, lovingly prepared for the printer and then put carefully away by the artist more than one hundred years ago, will be published for the first time in this beautiful volume. At last, Peale's life work, equivalent in scope and beauty to Audubon's Birds of North America, will be available to a wide audience. Titian Ramsay Peale II was the youngest son of Charles Willson Peale, the patriarch of the remarkable Pennsylvania family that contributed so much to the growth of art and science in the early years of the United States. His story is told in Kenneth Haltman's introductory essay, which also describes the art and science he brought to his life's work on butterflies.