Judy Bochenski was 15, wore mini skirts, and had to ask her parents if it was ok to cross the border into Red China.

John Tannehill was 18, and as he crossed, he sported the blue denim overalls that were the rage back home.

Glenn Cowan was 19, had shoulder-length hair, and wore purple bell bottoms. He waved goodbye to the media as he walked into the isolated nation.

It was April 10, 1971, and the teenage table tennis players were part of an improbable group of Americans who became the first to enter Communist China in two decades and begin a thaw that would evolve over 50 years.

Called “ping-pong diplomacy,” the encounter brought the long hair, blue jeans, rock-and-roll revolution of the United States face-to-face with the grim reality of Communism in China.

It was a crucial break in the bitter, sometimes bloody, rivalry between the two countries and led to President Richard M. Nixon’s visit to China the following year.

It would be a highlight of the lives of many of the nine America players. “It’s a wonderful legacy that I can leave to my family,” said Connie Sweeris, then a 23-year-old dental assistant from Grand Rapids, Mich.

But it would haunt Cowan, who later seemed lost out of the limelight and reportedly suffered from mental illness.

It would lead star Chinese player Zhuang Zedong to banishment amid political turmoil, and attempted suicide, according to his New York Times obituary.

And a year later it would result in a Rose Garden snub to the team that was the key to the breakthrough.

That Saturday in 1971, a delegation of nine players, four officials and two family members crossed from then-British Hong Kong into mainland China, becoming the first Americans allowed in since the Communist revolution in 1949.

The visit was an international sensation.

When Nixon was informed that Chinese premier Zhou Enlai had declared a new era in relations, the president marveled that such an announcement had been made “to a ping-pong team!”

The United States and China, which had been allies in World War II, had been ideological and military foes for over 20 years.

Their armies clashed savagely during the Korean War. And China was funneling aid to Communist forces then killing Americans in Vietnam, where the war was still underway.

But China remained backward and isolated. It had experienced a massive famine that killed tens of millions of people in 1950s and ’60s, and had undergone recurring waves of political repression.

Its ties to the Communist Soviet Union had frayed, and there had been a deadly border skirmish in 1969.

Subtle Chinese overtures to the outside world had been made.

“They have been dropping little hints...at the various embassies, and for months we’ve been expecting some thaw,” Nixon said, according to the transcript of a White House recording provided by the Richard Nixon Presidential Library and Museum.

But it happened in a way few foresaw. “You never can predict how the Chinese are,” Nixon said.

In the Spring of 1971, the World Table Tennis Championship was coming up in Nagoya, Japan.

Before leaving for the event, Roy Evans, the Welsh president of the International Table Tennis Federation, was invited to China, where the players were the best in the world and the sport was a national pastime.

China’s team was to attend the championship after a long absence, Evans wrote in the forward to a volume of Tim Boggan’s History of U.S. Table Tennis.

During a meeting in Beijing, Premier Zhou Enlai wondered what else his country could do to rejoin the international ping-pong fold.

Evans noted that teams from the top table tennis countries in the world would be in Nagoya, and it might be a chance to invite them to China.

Ping-pong wise, the United States was nowhere near that top tier.

“The Americans were little more than practice fodder,” the Los Angeles Times wrote, recounting the event in 2006.

Evans was therefore stunned when the United States was invited. But “I am convinced that the Chinese did exactly what the Chinese had planned to do,” he said.

Things had played out like this.

In Nagoya, Cowan, of Santa Monica, Calif., reportedly missed the American team bus to an event. The story was that he jumped aboard, or was invited aboard, the Chinese team bus.

An exotic figure with his long hair, Cowan was ignored by the buttoned-up Chinese players, except for the star, Zhuang Zedong, 30.

By most accounts, he came forward, greeted Cowan and gave him a silk-screen of China’s majestic Huangshan mountains he had with him.

Many years later in an interview with the Reuters news agency, Zhuang said he told Cowan through an interpreter: “Although the US government is unfriendly to China, the American people are friends of the Chinese. I give you this to mark the friendship from Chinese people to the American people.”

Cowan said at the time: “I got on their bus and I laid my rap on them. I told them I knew what it was like to be oppressed.”

Cowan, who had almost been barred from the U.S. team because of his hair, later searched Japanese shops for a gift he could give Zhuang.

He found a T-shirt bearing a peace symbol and the title of the Beatles’ hit song, “Let It Be.” (Cowan died during heart surgery in 2004. Zhuang died of cancer in 2013.)

The incident made headlines, and before the tournament ended, China extended invitations to teams from Canada, Britain, Colombia, Nigeria and the United States.

For the players, it was a shock. Should they go? Would they be safe in a such a hostile country?

Korean American player Dal Joon-Lee, whose father, two brothers and a sister were killed in the Korean War, declined.

“In the old country we were forbidden to speak to Communists,” he told the New York Times in 1972. “We were very much afraid of them.”

Judy Bochenski, now Judy Hoarfrost, 65, was the youngest member of the team, and had to get her parents’ permission. They were schoolteachers back in Eugene, Oregon.

“I really did want to go,” she said in an interview Tuesday. “I knew it was a huge deal. . . . I knew China was very isolated. I knew they were under a Communist system. . . . I knew there was some question about whether we would be safe.”

“I felt, ‘Of course we’ll be safe,’ ” she said. “ ‘We’re being invited by the Chinese team and the government. They’re not going to invite us and not treat us well.’ ”

She called home from Japan. Her father, Lou, said: “Yes, you should go.”

The team flew from Japan to Hong Kong, took a train to the border, and crossed a railroad bridge on foot.

“That was pretty momentous,” she said. The Chinese revolutionary anthem, “The East is Red,” was blaring. (She later learned how to sing it.) And tea was served.

The delegation then traveled to Guangzhou and Beijing.

“China looked and smelled and felt different,” she said. There were few cars, but masses of bicycles, and, outside the cities, ox carts. Huge portraits of Communist Party chairman Mao Zedong were everywhere.

Men and women all wore what the Americans called “Mao suits . . . baggy pants and baggy jackets … all very dark muted gray or brown dull colors,” she said.

“Everybody, to our eye, looked like they were dressed alike,” she said — except for the green-clad extremists known as “red guards.”

Several exhibition matches were played. At one venue, there were 18,000 people.

The Chinese players were world class. The Americans were not. “Our team was maybe, at best, 25th, in the world,” she said.

The games were called “friendship matches.”

“I played four matches overall . . . and I won three of them,” she said. “You can put ‘won’ in quotation marks.” The Chinese were going easy on the Americans.

“I knew what was going on,” she said.

When they returned from China, the Americans were media stars. They made the cover of Time Magazine.

A Chinese ping-pong team was invited to the United States, and visited the White House the next year.

During the Rose Garden ceremony, the Chinese players gathered with Nixon, while the U.S. players were stuck behind a rope line.

Player Connie Sweeris recalled that Nixon “kind of walked by us . . . and [someone] said, ‘Wouldn’t you like to meet the American team that went to China?’ ”

Nixon stopped and greeted the players.

But “we all felt a little snubbed,” Sweeris said.

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