By Steve Jones, About.com Guide

In early 1972, the United States and China had no diplomatic relations. That changed in February of that year when U.S. President Richard Nixon flew to Beijing (then commonly called Peking) and broke 22 years of Cold War tension between the two countries.

Background

In 1949, following years of civil war, Mao Zedong's Communists defeated Chiang Kai-shek's Nationalists for control of the country. Chiang and his party retreated to the island of Taiwan, which the United States quickly recognized as the sole Chinese government.
The U.S. was committed to its anti-Communist foreign policy in the wake of the Soviet Union's unabashed takeover of territory after World War II. In fact, Soviet leader Josef Stalin had promised to help revolutionary Communist movements around the globe, and he and Mao had formed an alliance. Mao also based much of his governmental policies around Soviet Stalinism.
U.S./Chinese relations deteriorated in the 1950s. American soldiers fought Chinese troops in the Korean War (1950-53), and President Dwight D. Eisenhower threatened armed intervention when mainland China appeared ready to attack Taiwan.

Sino-Soviet Split

Later in the 1950s, however, a crack developed in Sino-Soviet relations. When Stalin died in 1953, his successor as Nikita Khrushchev began to distance himself from Stalin's oppressive, dictatorial style. That alarmed Mao since he had patterned himself after Stalin.
Khrushchev later began cutting monetary and technological aid to agricultural China. Desperate to industrialize, Mao instituted what he called "The Great Leap Forward" -- a plan to have all rural Chinese people begin making "steel" from scrap metals.
Chinese neglected their crops and instead made worthless metal products. As crops failed, people starved. Between 1958 and 1961, some 30 million Chinese died. For their effort, China was no closer to becoming an industrialized nation.
Internally wounded, China was also increasingly isolated on a global scale. As border fighting broke out between Chinese and Soviet troops, China found itself pitted against its old ally and still cut off from the Western world by the American policy of containment.

Exploiting The Breach

Enter Richard Nixon. Nixon had made a political reputation after World War II by chasing Communists. He gained national fame by leading an investigation of accused Communist Alger Hiss, and he parlayed that notoriety into eight years as Eisenhower's vice-president. Eisenhower struck a relaxed, affable posture as president; he left strong-arm anti-Communism to Nixon and his secretary of state John Foster Dulles. Nixon again became famous for debating Khrushchev on the merits of capitalism versus communism in a mock-up of a modern kitchen at a Moscow exhibition.
Nixon lost the 1960 presidential race to John F. Kennedy, as well as the 1962 California gubernatorial race. Still, private-citizen Nixon kept up with foreign affairs, and he keenly watched the widening Sino-Soviet rift.
Nixon won the 1968 U.S. Presidential race, and as soon as he took office in 1969, Nixon set his National Security Advisor Dr. Henry Kissinger to begin exploiting China's isolation.

Nixon Goes To China

Popular foreign policy mythos holds that only a tough anti-Communist red-baiter like Nixon could confidently "go to China" and open a dialogue with the Red Chinese. (The idea even made it into popular culture in Star Trek VI: The Undiscovered Country: When Admiral Kirk, who had fought Klingons his whole career, opened "rapprochement" talks with Klingon officials, Spock wryly commented, "Only Nixon could go to China.")
However, as Tom Switzer has correctly observed at the National Review Online, others could have "gone to China." President Lyndon Johnson had suggested reconciliation with China as early as 1966. Strict 1949-style conservatives, not just liberals, were already questioning the efficacy of containment in light of the Vietnam War.
Still, Nixon was the one who did it. He had Kissinger, via a secret trip to Beijing, secure an invitation from Chinese Premier Zhou Enlai for Nixon to visit. Just as Nixon wanted to negotiate through American power to end the Vietnam War, he wanted to do the same with China. As much as he saw warming relations as beneficial to both China and the U.S. (as well as a critical new wedge against the Soviet Union), Nixon wanted China to appear the beneficiary.
The invitation came, and Nixon announced in mid-1971 that he would travel to China in February 1972. He also began loosening trade restrictions with China.
Nixon touched down in Beijing on February 21. He immediately met with his old Cold War-rival Mao, and over the next week he had a series of meetings with Zhou.
On February 28, the last day of Nixon's trip, the U.S. and China jointly issued what is now known as the "Shanghai Communique." The communiqué indicated that the United States and China pledged to work toward normalized relations. They also found diplomatic language that enabled them to temporarily set aside the testy issue of American recognition of Taiwan so they could move forward. As the U.S. State Department says, "The United States acknowledged the Chinese position that all Chinese on both sides of the Taiwan Strait maintain that there is only one China and that Taiwan is part of China."
Nixon's trip did not immediately normalize relations with China. That came in 1979, but it did open the door for an American-Chinese relationship that ultimately helped end both the Vietnam War and the colossus of the Soviet Union.
Non-Web Source: Thomas G. Patterson, J. Garry Clifford, and Kenneth J. Hagan, American Foreign Relations: A History, Since 1865 (Boston: Houghton Mifflin, 2000), pp 362-65.