Feininger returned to Paris in 1904 for 2 years where he met students of Matisse, which encouraged him to work more openly with colour and looser forms. After returning to Germany he became a member of the 'Berliner Sezession' in 1909 and exhibited at their show for the first time one year later.

The artist travelled back to Paris in 1911 for his exhibition at the 'Salon des Independants'. Here he had his first encounter with Cubism. Attracted to the vivid, faceted paintings Feininger began to explore cubism, breaking his forms into planes of colour, his chosen subject was the city; for Feininger, German towns with their Gothic cathedrals and surrounding landscapes were his inspiration. . In 1913 Franz Mark invited Feininger to exhibit his works with the German “Blue Rider” group, whose members advocated an expressive, abstract style, which appealed to the young Feininger. His friendships with Wassily Kandinsky, Klee, and Alexei von Jawlensky began at this time, and later, in 1924, the four artists founded the Blaue Vier group. In 1919, he joined the faculty of the Bauhaus, where he taught alongside the leading modern artists and architects of the day. Feininger remained on the Bauhaus faculty until the Nazis closed the school in 1933. Up until this time, his art was collected and featured in many museums throughout Germany, but under Hitler’s rule, his works and those of his fellow modern artists were banned and removed from public view.

After the Nazis came to power the situation became unbearable for Feininger and his wife, who was partly Jewish. They moved to America after his work was exhibited in the 'degenerate art’ exhibition in 1936. Feininger returned to the United States in 1937 and landed in New York, where he had not lived since his departure in 1887. In the same year the National Socialists confiscated more than 400 of his works. He moved to California, where a number of German émigré artists had settled, and began teaching at Mills College in Oakland. In 1938 he moved permanently to New York, and was invited to provide murals for the 1939 New York World’s Fair. Feininger's artistic breakthrough in the US only came in 1944 with a retrospective exhibition at the Museum of Modern Art in New York. In 1945 Feininger ran a summer course at the Black Mountain College in North Carolina, where he met Gropius and Einstein. His teaching, his writing and his later watercolours were an important source for the development of Abstract Expressionism in America.

Feininger worked with equal ease in many media: oil painting, watercolour, and woodcut. He focused on a limited range of subjects, most with clear architectural motifs: views of the city with its factories and harbors, architectural landscapes, all portrayed in prisms of luminous, transparent color. From the 1940s on, his work received much acclaim, and he received awards from the Metropolitan Museum and the Worcester Art Museum. Feininger passed away in New York on January 11, 1956 at the age of eighty-four.