Joan Hinton, a native Chicagoan who worked on the Manhattan Project to build an atomic bomb during World War II, then moved to China and spent the rest of her life as a devoted follower of Mao Zedong, died June 8 at a hospital in Beijing. Her son said she had an abdominal aneurysm. She was 88.

In 1948, Hinton took the dramatic step of following her brother, a diplomat, to China just as the country was in the throes of the Communist revolution led by Mao. Hinton, who witnessed the first atomic bomb explosion in 1945, was upset when nuclear energy was used to annihilate much of the Japanese cities of Hiroshima and Nagasaki during the waning days of World War II. She renounced the violent use of atomic energy and moved to China, where she thought an ideal socialist state would emerge based on Mao’s teachings.

During the Red-baiting era of the 1950s, Hinton was condemned in overheated magazine articles as a “a blond traitor,” a “Cold War Mata Hari” and a “femme fatale with a vengeance” who divulged atomic secrets to the Chinese.

She laughed off the accusations as preposterous.

“What a silly fuss,” she told The Washington Post in 1978. “When I arrived in the liberated area of China, they had nothing. We scoured the battlefields for old metal to make cooking pots. The last thing in anybody’s mind was the development of an atom bomb.”

Nonetheless, Hinton remained an ardent supporter of Mao, the Chinese Communist leader who controlled the country from 1949 until he died in 1976. Even after Mao’s Cultural Revolution reshaped Chinese society by force, leaving tens of millions of people dead in ideological purges, Hinton’s loyalty was undiminished.

“I was 100 percent behind everything that happened in the Cultural Revolution,” she said in 2008, long after most Chinese people had abandoned Maoist beliefs. “He was a terrific person, and he liberated all the people — he was not a monster at all.”