After The First World War Drambuie began to exploit new international opportunities. As it began to gain a foothold in America, prohibition struck. Initially this was a problem for Drambuie, with supplies no longer legally allowed to enter America. Many distillers and drink producers began to participate in the secretive Sub Rosa campaign, where pirates & smugglers were used to get Scottish spirits into America. In fact there is a recorded instance of Drambuie being seized by US Customs officers en route from Canada in 1931.