Cambridge University scientists, James Watson and Francis Crick determined the structure of the double helix, the twisted-ladder structure of deoxyribonucleic acid (DNA) on February 28, 1953.
Their work was aided by use of Rosalind Franklin's X-ray photographic work showing crystallographic evidence of the structure of DNA, which was shown to them, without her knowledge. Watson and Crick were awarded the Nobel Prize in 1962. More