National Open was painted in 1968, the year in which the United States Open golf tournament was played at the Oak Hill Club in Rochester, New York, and was won for the first time by Lee Trevino. Morley, who was living in New York City at the time and teaching at the School of Visual Arts, created National Open from a poster advertising the event. In this way the painting is closely related to Morley's paintings of ocean-going liners, derived as they are from advertising images, and painted by the artist in a precisely rendered realist style. The painting has a white border, with which "Morley sealed in the illusion, bracketed it, always bringing the eye back to the surface, never letting it get lost in the illusion of space...The reality, twice removed, was a surface realism that had to do with the snapshot, the reproduction, the two-dimensional image of reality" (ed. G. Battcock, Super Realism: A Critical Anthology, New York 1975, pp. 176-177).