1: 2: 3: 4: 5: 6: 7: 8:
category3 numcategory4 numitems4 19th Century 1 96 20th Century 1 39 Airmail - U.S. and Worldwide 1 43 Back-of-the-Book 1 14 Colonial and Early Territorial 1 14 Local Posts 1 13 Postal Stationery 1 1