Mao met farmers, merchants, local officials, an imperial scholar, even disaffected youth. He noted, in colourful detail, who felt oppressed by whom, how the classes interacted, and how control of property was key to wealth and power.
Assisting Mao was a 24-year-old local named Gu Bo, the grandson of landowners. His family was renowned for sending many scholars over the centuries to serve the emperor. But Gu Bo wanted change.
"He thought the old system was unfair," says his grand-nephew, Gu Anjian, who lives in a village near Changning. "So once he joined the Communist revolution, he burned down his grandfather's house."
China's Communist Party came to power promising to end the country's traditional class structure. As it turned out, it turned the class structure on its head. Scholars, landowners and merchants, the former privileged classes, were stripped of their rights, and sometimes of their lives. Villagers and workers were, for a time, elevated, in status and opportunity.China: What happened to Mao's revolution? (BBC)
More than 60 years on, farmers and workers are again at the bottom of the heap, and while there's a growing middle class, China has one of the world's biggest and fastest-growing rates of income disparity.
...But in China, being connected to the state, or the Communist Party, doesn't mean you're not capitalist. More than 90% of China's richest people are Party members, according to the Hurun Report, which tracks the country's wealthy.
China's national anthem may exhort the downtrodden, "arise, those who refuse to be slaves," but these days, those who want to get rich join the Party, and the Party wants the rich to join it. That way, wealth stays concentrated in the hands of its members, who have little incentive to change the system.
The richest 75 members of China's legislature, the National People's Congress, have an average net worth of $1.2bn.