Cookie jars are utilitarian or decorative ceramic or glass jars often found in American and Canadian kitchens. In the United Kingdom, they are known as biscuit barrels or biscuit jars. While used to store actual cookies or biscuits, they are sometimes employed to store other edible items like candy or dog treats, or non-edible items like currency (in the manner of a piggy bank). They became popular in America around the time of the Great Depression in 1929. Early American cookie jars were made of glass with metal screw-on lids. In the 1930s, stoneware became predominant as the material for American cookie jars. See "Cookie jar". Wikipedia. 2015-11-24.