Towards the end of 1864, Nesbitt (the contractor for furnishing the Post Office Department with stamped envelopes and newspaper wrappers) had considerable financial trouble in living up to his obligations and, at his earnest request, Congress passed a bill for his relief. As the then existing contract expired Sept. 11, 1864, the Post Office Department entered into a new agreement with Nesbitt, paying an advanced rate to the contractor and ordering a change of the dies of the two, three and six cents values. At present we are interested only in the change of the two cent die. In its new form the general features have been retained, but the inscription is altered to read "U. S. POST" and the shape of the stamp is either narrow or broad. The narrow die is called by the cataloguer "DIE C" and the broad one "DIE D." Using the system of line prolongation which has been already fully described, we are at once in a position to handle the large number of varieties and to collect them systematically. C Dies. (24 to 25 mm. width) Class II Var. 1 and 2. Bust points to intersection of 2nd and 3d stroke of "W." " III " 3 to 9. " " to last stroke of "W." " IV " 10 to 13. " " to left line of "O." " V " 14 to 16. " " to middle of "O." D Dies. (25-1/2 to 26-1/4 mm. in width.) Class III Var. 17 to 21. " IV " 22 to 27. " V " 28 to 40. As these varieties have never been thoroughly described and classified and as there are but few collectors who have recognized the great philatelic value of the Jackson dies, the writer desires to place himself on record with a prophecy; _i. e._ that as soon as the general collector knows how to find and to easily recognize the different varieties of "U. S. POST," these dies are going to be sought after enthusiastically. To assist those who desire to become better acquainted with them it will do no harm to give some additional information, showing how the writer has studied the varieties and what means he has employed to differentiate the several varieties belonging to one class. Although the description of the varieties accompanying the cuts, should be sufficient for the identification of any die variety, the writer has found that a system of line prolongation is very useful whenever, due to die deteriorations, a stamp appears to possess features which are not found in the descriptions. The system is based on the position of five letters which differ greatly in many varieties. These letters are:-- 1) "U" of "U. S." 2) "P" of "POST." 3) "T" of "POST" 4) "W" of "TWO." 5) "E" of "CENTS." and the measurements are made as follows: The left stroke of "U" is prolonged downward. Observe the line with regard to letters "O, C, E" and "N." The upright stroke of "P" is prolonged downward. Observe line with regard to letters "C" and "E."