John Koopman’s, taught by the well-known artists Robert Henri and William Chase, worked mainly in genre art, landscapes, and maritime motifs. He had exhibitions at the Art Institute of Chicago, Detroit Institute of Arts and The Pennsylvania Academy of the Fine Arts and was a member of various artists’ associations, including the American Water Color Society and the Society of Independent Artists. Koopman was the head of the Art Department of the Brooklyn Institute and worked as a teacher at the Grand Central School of Art.