I Congress. I Session. Chap. 16, Sept., 1789 I " II " " 36, Aug., 1790 I " III " " 23, March, 1791 II " I " " 27, Feb., 1792 III " I " " 23, 8 May, 1794 V " III " " 41, 2 March, 1799 XI " II " " 37, 30 April, 1810 XIII " III " " 16, 23 Dec., 1814 XIV " I " " 7, 1 Feb., 1815 XIV " I " " 43, 9 April, 1816 XIX " II " " 61, 3 March, 1825 XX " I " " 61, 3 March, 1827 XXVII " II " " 43, 2 March, 1845 The earliest letters which we have seen, consist of single sheets of paper folded and addressed upon the sheet. An envelope would have subjected them to double postage. They are penmarked with the name of the mailing office, the date occasionally, the amount of the postage paid or due, generally in simple figures, sometimes with the word "cents" in full or abbreviated, added. Gradually, hand stamps were introduced. At first the name of the mailing office in a simple frame, generally circular, the month and day being still written in with a pen, and the amount of postage written as before. A further improvement appears later on in the introduction of the month and day as part of the hand stamp. The word "paid" or "due," the amount of postage in figures or with "cents," either written or hand stamped, always added. And finally all the marks are included in one hand stamp. There was evidently no uniformity of practice, except the general requirement that the name of the mailing office, the month and day, and the amount of postage should in some form be marked on the letter. Improvements seem generally to have originated in the larger offices, but smaller offices sometimes took the lead in enterprise. An improvement once adopted does not seem always to have been adhered to; letters mailed at the same office on the same day and differently marked may be frequently found in old files. The hand stamps seem to have been obtained by the several offices for themselves, as there is no uniformity of style. Some of these hand stamps are curious enough to warrant a brief description, and it would be difficult to lay down a rule which would distinguish some of them from the stamps we admit to our albums.