“This is an historic occasion”, announced Francis Crick on 2 June 1966, as he began the opening address of the annual meeting of molecular biologists at Cold Spring Harbor. “There have been many meetings”, he continued, “about the genetic code during the past ten or twelve years but this is the first important one to be held since the code became known.” Such bold pronouncements usually guarantee that an occasion will linger in history's footnotes and never shine centre-page. But, as the first public presentation of the complete genetic code, the moment had some claim to being historically complementary to the publication of James Watson and Crick's first paper in Nature. In April 1953, in fourteen paragraphs and a diagrammatic sketch (contributed by Odile Crick), they had announced—with a minimalism that came more of urgent certainty than of diffidence or reticence—not just a physical structure for DNA, but something far more. “It has not escaped our notice that the specific pairing [of purine and pyrimidine bases] we have postulated immediately suggests a possible copying mechanism for the genetic material.” The trajectory begun in 1953 with the suggestion of “a possible copying mechanism” completed its public arc at Cold Spring Harbor in 1966 with a very specific and (almost) complete table showing the genetic code. The occasion “marked”, as Crick later judged, “the end of classical molecular biology”.