His works as an artist have been classified as late Surrealist and precursory to Pop Art.Copley’s work from his start as an artist in the early 50s and into his career experienced an evolution in ideas. Copley’s paintings throughout the 1950s and 60s dealt with ironic and humorous images of stereotypical American symbols like the Western saloon, cowboys, and pin-up girls combined with flags. His works during this period were often considered a combination of American and Mexican folk art and melded in well with the new young POP movement occurring in America when he returned to New York in the 1960s. Artists like Andy Warhol, Christo, Roy Lichtenstein and many others were frequent visitors at Copley’s studio on Lower Broadway. Copley believed that pop art had always interested him, claiming American pop art had much to do with “self-disgust” and “satire.”Copley’s works in the 1970s focused on his own understating of differences and challenges between men and women in romantic and sexual relationships. His works were now erotic, even pornographic. In 1974 he exhibited these new works at what was then the New York Cultural Center in Columbus Circle, New York in a show titled “CPLY X-Rated.” These pieces were a sudden change from his previous romantic whimsical periods. The American public had difficulty with the material, for which Copley expressed, “Americans… don’t know the difference between eroticism and pornography. Because eroticism has always existed in art. And pornography has never necessarily been in art.” Copley’s experienced greater feedback in Europe, where the work was then well received. In conjunction with the New York Cultural Center Show there was a special “CPLY X-Rated Poster and Catalog.
Copley’s first exhibition took place in Los Angeles in 1951 at Royer’s Book Shop. From there Copley participated in numerous solo and group exhibitions worldwide. In 1961, Copley was given an exhibition in Amsterdam by the Stedelijk Museum. The museum became the first public institution to add a Copley to their collection.