The home and farm visit lasted about an hour, and Kimberley said he was impressed by Xi's knowledge of agriculture. "The questions he asked about agriculture, I knew he knew quite a bit about it."

The visit put Kimberley on a path to promote agricultural exchanges between the US and China. By his own account, Kimberley has visited China about 20 times since Xi's visit to his farm. He is involved in a major project to build a Kimberley Farm model in Hebei to help China farm more efficiently.

During Xi's second visit to Iowa, then governor Branstad hosted a state dinner in honor of Xi.

Kenneth Quinn, former president of the World Food Prize Foundation and former US ambassador to Cambodia, was especially touched by one particular remark made by Xi at the dinner.

"He quoted Mark Twain, who wrote about 19th-century life along the Mississippi River and American Midwest. He spoke about how the memories of seeing the sun over the Mississippi River were so deeply ingrained within him," Quinn said. "I could not recall ever hearing a foreign leader speak so movingly about my country. That brought home to me the power of citizen diplomacy."

The next day, while escorting Xi to the agricultural symposium there, Quinn told Xi that he might be one of the few Iowans who shook Xi's hand as well as Xi's father's hand, when Xi Zhongxun went to Iowa in 1980.

"The vice-president literally stopped in his tracks; his eyes got very big, a big smile on his face, and he said to me, 'You have two very interesting stories,'" Quinn said.

Xi Zhongxun visited Iowa in 1980 as the governor of Guangdong province, while Quinn, as a Pearson fellow at the US State Department, was tasked to escort the senior Xi around Iowa.

To this day, Quinn said he believes that the senior Xi's visit to the Amana Colonies, a former communal living structure, might have helped China's leaders push for agricultural reform in China, which dramatically increased China's food production.

Later, Quinn commissioned a local artist to do a painting about Xi's and his father's visits to Iowa with the president's words as the title Two Interesting Stories. It now hangs at the World Food Prize Hall of Fame.

Quinn said the bonds forged between Xi and Iowans prove that the US and China, which have quite different philosophies of governance, could have a genuinely friendly relationship. "There could be this experience that would be so meaningful that it could override some of the other irritants in the relationship," Quinn said.