Once a Danish colony, the U.S. Virgin Islands was once a stamp-issuing "country" of its own: Danish West Indies. These stamps were issued between 1856-1915. The United States purchased the islands in 1917, at which time the name was changed. The islands consist of only 132 square miles, with St. Croix the largest. Charlotte Amalie is not large, although it has grown substantially since the view shown on the 1937 postage stamp. In its early years St. Thomas was the world's biggest slave market. Today the slave market area is covered by open -air stands on Market Square.