Postage Due, Domestic Covers

From 1876 until 1976, the postage due collected upon delivery of letters bearing no prepaid postage was double the amount of postage required had the postage been prepaid. The ordinary domestic letter rate was 20 cents from 1921 until 1967. These two covers from 1926 and 1944 illustrate the collection of 40 cents due on unpaid domestic letters as indicated by the crayon manuscript markings.