Amid a discussion of trade in 1973, Chinese leader Mao Zedong made what U.S. Secretary of State Henry Kissinger called a novel proposition: sending tens of thousands, even 10 million, Chinese women to the United States.

"You know, China is a very poor country," Mao said, according to a document released by the State Department's historian office.

"We don't have much. What we have in excess is women. So if you want them we can give a few of those to you, some tens of thousands."

A few minutes later, Mao circled back to the offer. "Do you want our Chinese women?" he asked. "We can give you 10 million."