Wedding Traditions: The wedding Ring

But before the 1900s, a diamond engagement ring was a luxury item; in fact, engagement rings even without a diamond setting were considered extravagant. The Archduke Maximilian of Austria gave one to Mary of Burgundy in 1477, but it was hardly commonplace.

It was a diamond company that would change that. In the late 1800s, the diamond market was flooded when big diamond mines were found in South Africa, and that new influx of gems drove the prices down. 

In 1939, De Beers hired N.W. Ayer & Son as their ad agency to help them rebound from the slump in sales they'd had as a result of the South African mines. And a new wedding tradition was born: Diamond sales rose 55 percent between 1938 and 1941, and by 1948 America was introduced to the "A Diamond Is Forever" ad campaign -- and a new engagement tradition swept the U.S.