Leonard Nelson, American, 1912 to 1993, abstract oil and acrylic on canvas painting. Signed by the artist and dated 1976 to the back. From the artists estate, numbered 259. Framed. Leonard Nelson had a career as a prolific artist and influential art educator that spanned more than half the twentieth century, from the 1930s to the 1990s, and forged close links with the leading artists and movements of that time in American art history. Abstract Paintings And American Art Collectibles.