Hansen was the son of Herman W. Hansen, illustrator and painter of cowboys and horses. Hansen attended the Mark Hopkins Institute (San Francisco) under Arthur Mathews, but his studies were cut short by the closing of the school on account of an earthquake (1906).
Hansen set off for Europe, arriving in Hamburg, the birthplace of his father, in 1906. He was immediately taken with the work of Carlos Grethe and so enrolled at the Royal Academy in Stuttgart where he was able to study with Grethe. The summer of 1908 was spent along the Belgian coast at the resort of Nieuwpoort where Grethe often painted. By 1910 Hansen was in Belgium and there began to make prints. He was invited to exhibit at the Brussels Universal Exposition of 1910 and at the Salon des Printemps (1911, 1912 Brussels). During this period Hansen earned money and gained material for his work by shipping out on merchant and fishing craft in the North Sea.
In 1912 Hansen returned to San Francisco, where he taught at the University of California. By 1916 he was settled in Monterey where he worked on the sardine fleet at night and painted during the day. The turning point in his career came in 1918 when he met William Ritschel who arranged his first one man show in New York, which was quite successful. In 1922 he married Frances Rives. Hansen, along with Arthur Hill Gilbert, ANA, was instrumental in the founding of the Carmel Art Association.
The diploma portrait of Hansen is by Gerald Leake. Milch Galleries handled his work in New York.
