The earliest stories about these events have been known to originate in Brussels, Belgium around 1860. A frequently quoted legend traces the origin of this practice to the 16th or 17th Century Netherlands. However, there are also parallels with many dowry practices and the U.S. colonial or hope chest (trousseau) custom.
There no such custom in the U.K., where wedding presents are normally selected from a list provided by the couple, and delivered either at the wedding or by the shop, and sometimes displayed at the wedding. A related custom practised in medieval England was the Bride Ale; in Langland's Piers Plowman (§ B.II.45) there is a reference to a bruydale. This was a feast held before the wedding day, at which the bride made beer and sold it to the guests at a high price.
The earliest use of this sense of the word in print may be in the Grand Rapids Michigan Evening Press 22 June 4, 1904: "The ‘shower parties’ that through mistaken hospitality the wedded couple are forced to attend..." And may derive from the custom in Victorian times for the presents to be put inside a parasol, which when opened would "shower" the bride-to-be with gifts."