Leaving Paris shortly before World War I, he returned to his father's house, but was denied support. For the next 17 years, Maurer painted in a garret in his father's house, and gained no critical acclaim. However, he took part in exhibitions at the Anderson Galleries and others. He exhibited regularly at the New York Society of Independent Artists and was elected their director in 1919. In 1924 the New York dealer Erhard Weyhe bought the contents of Maurer's studio and represented the artist for the remainder of his career.