The effort to discover the structure of DNA was a race among several players: world-renowned chemist Linus Pauling at the California Institute of Technology, X-ray crystallographers Maurice Wilkins and Rosalind Franklin at Kings College London, and Watson and Crick at the Cavendish Laboratory, Cambridge University.
The competitive juices were flowing well before the DNA sprint was in high gear. In 1951, Pauling narrowly beat scientists at the Cavendish Lab, a top center for probing protein structure, to the discovery that proteins are arranged in structures called alpha-helices. The defeat stung. When Pauling sent a paper to be published in early 1953 that proposed a three-stranded DNA structure, Sir Lawrence Bragg—the head of Cavendish—gave Watson and Crick permission to work full-time on DNAs structure. Cavendish was not about to lose to Pauling twice.
Pauling's proposed three-stranded helix had the bases facing out. While the model was wrong, Watson and Crick were sure Pauling would soon learn his error. They estimated that he was six weeks away from the right answer. Electrified by the urgency—and by the prospect of beating a science superstar—Watson and Crick spent four weeks obsessing about DNA in endless conversations and bouts of model-building to arrive at the correct structure.
In 1952, Wilkins and the head of the Kings laboratory denied Pauling's request to view their X-ray photos of DNA—crucial evidence that inspired Watson's vision of the double helix. Pauling had to settle for inferior older photographs. In the same year, he was planning to attend a science meeting in London, where he most likely would have renewed his request in person. But it was the McCarthy era, and the U.S. State Department denied Pauling's request for a passport because of his "un-American" antiwar activism. It was fitting, then, that Pauling, who won the Nobel Prize in Chemistry in 1954, also won the Nobel Peace Prize in 1962, the same year Watson, Crick, and Maurice Wilkins won their Nobel Prize for discovering the double helix.