A 1971 photo of a woman holding pingpong paddles bearing caricatures of President Nixon and China's Mao Zedong recalls that year's Chinese-U.S. match in Dortmund, Germany, which led to Nixon's historic visit to Beijing. (Associated Press)

A 1971 photo of a woman holding pingpong paddles bearing caricatures of President Nixon and China's Mao Zedong recalls that year's Chinese-U.S. match in Dortmund, Germany, which led to Nixon's historic visit to Beijing. (Associated Press)