Joan Hinton (L) hugs an elderly Chinese woman. [Photo/CNDFILM]

Erwin Engst, known as Yang Zao in China, was a dairy-farming expert who came to China in October 1946 as an expert of the United Nations Relief Administration after selling his own pasture in America.

Inspired by Edgar Snow's Red Star Over China, he joined China's communist revolution and devoted his whole life to fueling China's agricultural development.

Engst first arrived in Shanghai before traveling to Changsha, Hunan province. The situation in the Kuomintang-controlled areas left him very disappointed.

After the Kuomintang launched the civil war, Engst decided to go to Yan'an in Shaanxi.

The huge difference between the liberated areas and the Kuomintang-controlled areas amazed Engst, and the confidence and optimism on the faces of the people in the liberated areas infected him.

When Engst saw that an army of only 20,000 people led by the Communist Party had defeated the 200,000-strong army of Hu Zongnan – the commander-in-chief of the First Route Army led by the Kuomintang – with the support of the people, he was particularly moved. He decided to stay in the liberated areas and invited his girlfriend Joan Hinton, or Han Chun, to China.

Hinton was a nuclear physicist and worked on the Manhattan Project in the 1940s. She came to China in 1948 and married Engst, who had been working as an advisor to the Chinese government since 1946.

Erwin Engst (L) and Joan Hinton (second from left) taste Mongolian snacks. [Photo/CNDFILM]

The couple devoted themselves to the development of the nation's dairy industry as well as its farm machinery sector. Both remained staunch supporters of the Chinese communist revolution.

When asked where she was most happy in her life, Hinton said the Sanbian pasture, which is in present-day Inner Mongolia autonomous region. She chose this location due to her love of the prairies and the people who live there.

Hinton and her husband received the task of constructing the Sanbian pasture in Inner Mongolia's Chengchuan town in 1949.

During their time with the farmers and herdsmen in Chengchuan, Engst was responsible for animal husbandry. Through scientific breeding, the dairy cow population increased in size and quality.

Hinton combined her expertise in science and engineering to make mechanized tools that helped farmers and herdsmen to increase milk production.

To commemorate the couple's spiritual commitment to international communism and their outstanding contributions to the improvement of livestock breeds and the prevention and control of animal diseases, a memorial hall was established in Inner Mongolia's Otog Front Banner.

The Engsts have a meal with a Chinese family. [Photo/CNDFILM]