This comprehensive monograph explores the conceptual complexity and diversity of Claes Oldenburg's early work to reveal the influential artist's extraordinary inventiveness. Accompanying an exhibition of Oldenburg's seminal early work, this publication examines in depth the breadth of his artistic career from the late-1950s to 1970. It features works including the landmark installations The Street and The Store and their accompanying Happenings; the highly influential spectacular sculptures of everyday objects, as well as drawings and preparatory collages for public projects from the 1960s. The book traces the development of Oldenburg's practice as it follows his work up to the Mouse Museum. Included also in the book is an extensive chronology, alongside notes as well as a variety of installation views that showcase the careful consideration given to modes of presentation. In addition to imagery of his infamous Pop icons, the publication includes illustrations of materials that have never been shown, such as notbooks pages, preparatory studies, photographs taken by the artist, drawings and collages, and clippings with amusing advertisements from the 1960s that served as models for his sculptures. Richly illustrated and including a wealth of previously unpublished materials, this volume probes diverse aspects of his work to offer fresh perspectives on Oldenburg's artistic development and unprecedented insights into the conceptual process of his artistic explorations.