Newton began his career as a mural painter, but, as the demand for murals died out in the early twentieth century, he turned to landscape painting, to which he devoted the rest of his life. His landscapes received critical praise and were widely exhibited.
Newton was a noted horseman, belonging to many hunts on Long Island, where he made his home. He was also something of an explorer, being one of the first to see the Kaieteur Falls in British Guiana, which he painted.
Newton belonged to many art societies, including the Salmagundi Club, the Boston Art Club, and the New York Municipal Artist Society.