He celebrated his first success in 1908 with the exhibition of his equestrian paintings. In the same year August Deusser founded the “Sonderbund” together with Max Clarenbach, Julius Bretz, Walter Ophey and some Rhenish painters - one of the most modern artists' associations in the Rhineland at the time. In their exhibitions they showed works by their French colleagues such as Claude Monet, Paul Cézanne and Henri Matisse.