Mr. Lincoln's unselfish magnanimity is the central marvel of the whole affair. His reply ended the argument. Mr. Seward doubtless saw at once how completely he had put himself in the President's power. Apparently, neither of the men ever again alluded to the incident. No other persons except Mr. Seward's son and the President's private secretary ever saw the correspondence, or knew of the occurrence. The President put the papers away in an envelop, and no word of the affair came to the public until a quarter of a century later, when the details were published in Mr. Lincoln's biography. In one mind, at least, there was no further doubt that the cabinet had a master, for only some weeks later Mr. Seward is known to have written: "There is but one vote in the cabinet, and that is cast by the President." This mastery Mr. Lincoln retained with a firm dignity throughout his administration. When, near the close of the war, he sent Mr. Seward to meet the rebel commissioners at the Hampton Roads conference, he finished his short letter of instructions with the imperative sentence: "You will not assume to definitely consummate anything." From this strange episode our narrative must return to the question of Fort Sumter. On April 4, official notice was sent to Major Anderson of the coming relief, with the instruction to hold out till the eleventh or twelfth if possible; but authorizing him to capitulate whenever it might become necessary to save himself and command. Two days later the President sent a special messenger with written notice to the governor of South Carolina that an attempt would be made to supply Fort Sumter with provisions only; and that if such attempt were not resisted, no further effort would be made to throw in men, arms, or ammunition, without further notice, or unless in case of an attack on the fort. The building of batteries around Fort Sumter had been begun, under the orders of Governor Pickens, about the first of January, and continued with industry and energy; and about the first of March General Beauregard, an accomplished engineer officer, was sent by the Confederate government to take charge of and complete the works. On April 1 he telegraphed to Montgomery: "Batteries ready to open Wednesday or Thursday. What instructions?"