A status symbol, the diamond engagement ring has been mythologized. But this marriage proposal tradition doesn’t date as far back as one might imagine. Prior to discovery of African diamonds in 1870, diamonds were rare and reserved for only the most exclusive and wealthiest patrons. In response to the discovery of the new, enormous cache of diamonds, Ernest Oppenheimer of De Beers Corporation hired the New York advertising firm N. W. Ayer & Son in 1938 to transform a diamond ring into an irresistible symbol of romantic love. The resulting “A Diamond is Forever” ad campaign (1947) was so successful that many consider it to be the best advertising scheme of the 20th century. Today, more than 80% of American marriages begin with a diamond engagement ring.