Page 7 - Demo

Over the decades in which an Air Mail service was offered by the Post Office, new stamps were issued regularly in denominations corresponding to changing postal rates, and to commemorate notable events, people, or places. In 1918, at the very genesis of Air Mail, it required a 24%u00a2 stamp to mail a one-ounce letter, of which 10%u00a2 was for Special Delivery. While the cost was calculated differently over the years, it eventually dropped to 5%u00a2 in 1928 for a letter weighing an ounce. During the 1930s and %u201840s, the rate rose and fell, returning again to a nickel an ounce by 1946. Then, it steadily climbed until the last domestic Air Mail rate was established in 1975. At that point, the price was set at 17%u00a2 for the first ounce of a letter, 15%u00a2 for each additional ounce, and 14%u00a2 for a postal card. In all, a total of 150 different Air Mail stamps were issued by the Post Office in the United States. The Scott Standard Postage Catalogue assigned them a C prefix, and they are numbered C1 through C150.