AES, DLC-RTL. Lincoln's endorsement appears on a letter from John P. Usher, March 8, 1865, tendering his resignation as secretary of Interior. Usher's covering letter of the same date is as follows: ``I thought it possible that the letter of resignation might be published; and I feared it would appear a little inconsistent to tender it, to take effect at so distant a day. I send it up by Mr. Dole, and, at his suggestion will name the 15th day of May as the date when the resignation shall take effect. If that pleases you the letter could be so endorsed and the nomination of my successor could be made to the Senate with a view to his appt. at that time. . . .'' (Ibid.).