The opening of the Ninth Street Show, otherwise known as the 9th Street Art Exhibition: A gathering of a number of notable artists, and the stepping-out of the post war New York avant-garde, collectively known as the New York School.

The 9th Street Art Exhibition of Paintings and Sculpture is the official title artist Franz Kline hand-lettered onto the poster he designed for the Ninth Street Show. Now considered historic, the artist-led exhibition marked the formal debut of Abstract Expressionism, and the first American art…