Of the many best loved traditions in America, the donning of costumes is at the top of the list. Many, many years ago, in times past, adults began dressing in elaborate costumes for Halloween parties, also known as Masquerade parties, long before it became an annual event for children. Dressing up in Halloween costumes is a recent tradition that developed in the twentieth century. The first store bought Halloween costumes were not available before the 1930's.