After World War 2, the art world underwent major changes and disruptions. Modernism shifted from Paris to New York City and took on a stricter formalism under the influence of Clement Greenberg. In Europe, art reflected existentialist themes of despair through works like Francis Bacon's painting. Abstract Expressionism emerged in New York featuring gestural paintings like Pollock's. Minimalism and Pop Art also emerged, simplifying forms and using imagery of mass culture. New movements challenged assumptions through Happenings, Conceptual art, and Land art. Architecture integrated sculpture and structure in works like Wright's Guggenheim Museum.