From the very beginning there had been threats to kill him. He was constantly receiving letters of warning from zealous or nervous friends. The War Department inquired into these when there seemed to be ground for doing so, but always without result. Warnings that appeared most definite proved on examination too vague and confused for further attention. The President knew that he was in some danger. Madmen frequently made their way to the very door of the Executive Office; sometimes into Mr. Lincoln's presence; but he himself had so sane a mind, and a heart so kindly even to his enemies, that it was hard for him to believe in political hatred deadly enough to lead to murder. He summed up the matter by saying that since he must receive both friends and strangers every day, his life was of course within the reach of any one, sane or mad, who was ready to murder and be hanged for it, and that he could not possibly guard against all danger unless he shut himself up in an iron box, where he could scarcely perform the duties of a President.