The present post-office organization dates from about 1836, as the period that followed that year was one of transition from stage-coach to rail car for the transportation of mails. As railway mail service was increased and extended, sometimes railroad companies made arrangements with contractors to handle it. Occasionally contracts were transferred to the contractors at the same rates received by the railroads. Frequently the compensation was divided pro rata as far as the railroad covered the route. It was not uncommon for postmasters in large cities to make the arrangements for the department. Naturally such a lack of uniformity of procedure and control invited irregularities of one kind or another, although they were for the most part not serious ones, and were eventually corrected and a system of standards and of unified control put into effect. _Origin of Mail Classes_ In 1845 any letter that weighed one half ounce or less was classified as a single letter without regard to the number of sheets it contained; a five-cent rate was charged for distances under three miles and ten cents for greater distances. In 1847 the postage-stamp was officially adopted and placed on sale July 1 of that year at New York. In the year 1848, 860,380 postage-stamps were sold; in 1890, 2,219,737,060 stamps were sold, and in 1921 there were issued to postmasters 14,000,000,000 adhesive stamps, 1,100,000,000 postal cards, 2,668,000,000 stamped envelopes, and 80,800,000 newspaper wrappers. In 1850 the rates were reduced to three cents for any distance less than three hundred miles, if prepaid, and five cents if not prepaid, and, for a greater distance, six cents if prepaid and ten cents if not prepaid. The prepayment of postage was finally made compulsory in 1855. In 1863 a uniform rate of three cents for single letters not exceeding one half ounce in weight was adopted for all distances, and twenty years later, in 1883, the two-cent letter was adopted. In 1917 the rates of three cents on letters and two cents for postal cards were adopted, the extra cent in each case being for war revenue. On June 30, 1919, however, the three-cent letter rate and the two-cent postal-card rate expired by limitation, and the two-cent letter rate and one-cent postal-card rate returned. When the parcel post was established in 1913, and the air mail service was inaugurated in 1918, special stamps were issued, although they were soon discontinued. Our friends who collect stamps may be glad to know that a philatelic stamp agency has been established under the third assistant postmaster-general at Washington, which sells to stamp-collectors at the face-value all stamps desired which are in stock and which may have special philatelic value to stamp-collectors. _Emergency Measures During the War_