Because the United States' Asian Exclusion Act prohibited legal immigration by Chinese women, once Gee was in San Francisco he never saw his mother again.

While in San Francisco, Gee lived in Chinatown and became friends with several avant-garde artists like Kenneth Rexroth, Jehanne Bietry-Salinger, John Ferren, Dorr Bothwell, and Ruth Cravath.

In 1926, Gee also founded the Chinese Revolutionary Artists' Club, where he taught classes in advanced painting techniques and theory.

[2] Its initial members were all young Chinese immigrant men, and it had a small studio in Chinatown (at 150 Wetmore Place), which provided much of their subjects.

"[4] Art historian Anthony W. Lee, examining Gee's position in the political spectrum at the time between the Chinese Communist Party and the nationalist Kuomintang, wrote that Gee, despite being close to the Kuomintang, probably saw "the club a potential ally of the CP and thought optimistically of a nationalist regime that would incorporate theories and organizational skills from the Soviet Union," although he "was not a doctrinaire Marxist and never joined the CP".

He quickly befriended prominent artists of the Parisian avant-garde and exhibited his work alongside them at the Salon des Indépendants.

[6] According to Wimmer's memoirs, during this period Gee was employed at a defense-industry company, worked six days per week, and returned home to paint at night.

He became an active fundraiser for causes in China, where one of his most notable efforts was the completion of a large mural on K Street as a contribution for the Chinese Flood Relief campaign.

He was heavily involved in the writing and stage design for "Kuan Chung's Generosity", a WPA Theatre project in 1930 and danced at the Institute of Chinese Studies.