Avery facilitated the birth of the New York Post-War Abstraction movement because of his friendship with Rothko and Gottlieb. A supreme colourist engaged by purely aesthetic concerns, Avery nevertheless remained faithful to depicting subject matter observed from the motif, even as his paintings became increasingly abstract. After his first heart attack in 1949, Avery’s style changed to one of extreme simplicity and quiet restraint. In 1959, when he painted Trees against the Sea, he was in failing health. His painting, however, was still airy, like a breath of colour on the canvas’s surface. In a commemorative essay on Avery, Rothko wrote, “Avery is first a great poet. He is the poetry of sheer loveliness, of sheer beauty,” and further on, “What was Avery’s repertoire? His living room, Central Park, his wife Sally, his daughter March, the beaches and mountains where they summered; cows, fish heads, the flight of birds; his friends and whatever world strayed through his studio: a domestic, unheroic cast.”