One matter, however, overshadowed all others. Nearly a year before, Washington had seen that there was no prospect or possibility of accommodation with Great Britain. It was plain to his mind that the struggle was final in its character and would be decisive. Separation from the mother country, therefore, ought to come at once, so that public opinion might be concentrated, and above all, permanency ought to be given to the army. These ideas he had been striving to impress upon Congress, for the most part less clearsighted than he was as to facts, and as the months slipped by his letters had grown constantly more earnest and more vehement. Still Congress hesitated, and at last Washington went himself to Philadelphia and held conferences with the principal men. What he said is lost, but the tone of Congress certainly rose after his visit. The aggressive leaders found their hands so much strengthened that little more than a month later they carried through a declaration of independence, which was solemnly and gratefully proclaimed to the army by the general, much relieved to have got through the necessary boat-burning, and to have brought affairs, military and political, on to the hard ground of actual fact. Soon after his return from Philadelphia, he received convincing proof that his views in regard to the Tories were extremely sound. A conspiracy devised by Tryon, which aimed apparently at the assassination of the commander-in-chief, and which had corrupted his life-guards for that purpose, was discovered and scattered before it had fairly hardened into definite form. The mayor of the city and various other persons were seized and thrown into prison, and one of the life-guards, Thomas Hickey by name, who was the principal tool in the plot, was hanged in the presence of a large concourse of people. Washington wrote a brief and business-like account of the affair to Congress, from which one would hardly suppose that his own life had been aimed at. It is a curious instance of his cool indifference to personal danger. The conspiracy had failed, that was sufficient for him, and he had other things besides himself to consider. "We expect a bloody summer in New York and Canada," he wrote to his brother, and even while the Canadian expedition was coming to a disastrous close, and was bringing hostile invasion instead of the hoped-for conquest, British men-of-war were arriving daily in the harbor, and a large army was collecting on Staten Island. The rejoicings over the Declaration of Independence had hardly died away, when the vessels of the enemy made their way up the Hudson without check from the embryo forts, or the obstacles placed in the stream.