The battles of that war (each is its place) have had their immediate results well defined. To see, as clearly their exact place in relation to the entire struggle, and that they were the legitimate sequence of antecedent preparation, requires that the preparation itself shall be understood. The camps, redoubts, and trenches, which engirdled Boston during its siege, were so many appliances in the practical training-school of war, which Washington promptly seized, appropriated, and developed. The capture of Boston was not the chief aim of Washington, when, on the third day of July, 1775, he established his headquarters at Cambridge. Boston was, indeed, the immediate objective point of active operations, and the issue, at arms, had been boldly made at Lexington and Concord. Bunker Hill had practically emancipated the American yeomanry from the dread of British arms, and foreshadowed the finality of National Independence. However the American Congress might temporize, there was not alternative with Washington, but a steady purpose to achieve complete freedom. From his arrival at Cambridge, until his departure for New York, he worked with a clear and serene confidence in the final result of the struggle. A mass of earnest men had come together, with the stern resolve to drive the British out of Boston; but the patriotism and zeal of those who first begirt the city were not directed to a protracted and universal colonial resistance. To the people of Massachusetts there came an instant demand, imperative as the question of life or death, to fight out the issue, even if alone and single-handed, against the oppressor. Without waiting for reports from distant colonies as to the effect of the skirmish at Lexington and the more instructive and stimulating experience at Breed's Hill, the penned the British in Boston and determined to drive them from the land. Dr. Dwight said of Lexington: "The expedition became the preface to the history of a nation, the beginning of an empire, and a theme of disquisition and astonishment to the civilized world." The battle of Bunker Hill equalized the opposing forces. The issue changed from that of a struggle of legitimate authority to suppress rebellion, and became a context, between Englishmen, for the suppression, or the perpetuation, of the rights of Magna Charta. The siege of Boston assumed a new character as soon as it became a part of the national undertaking to emancipate the Colonies, on and all, and thereby establish one great Republic. From the third of July, 1775, until the seventeenth of March, 1776, there was gradually developed a military policy with an army system, which shaped the whole war.