An army of invasion gathered rapidly in Washington, seized Arlington, General Lee's ancient family estate, on the Virginia shore of the Potomac, for a drill ground, took possession of recalcitrant Maryland, and made of all railroads entering the capital the highways and instruments of war. Winfield Scott, the old and vacillating general of the regular army, was quickly set aside, and the able General Irvin McDowell took his place. Thirty thousand troops moved slowly into Virginia under the pressure of public opinion stimulated by newspaper editors, ministers of the Gospel, and stiff-backed Republicans, who, like similar classes in the South, declared that the war was to be over in three months. Other armies collected at Cincinnati under young George B. McClellan, soon to be major-general, at Louisville under Don C. Buell, and at St. Louis under the erratic John C. Fremont. When Congress met, all these movements were quickly ratified, and the two sections of a country of more than thirty million people, all supposed to be devotees of commerce, industry, and agriculture, "worshipers of money," entered with unparalleled eagerness upon a war which was soon to surprise and even appall the world. What industry lost in the North by secession of the South was regained in the manufacture or preparation of military supplies for soldiers who fought the South; and in the Confederacy men who knew little of industry and of seafaring soon established great plants where the munitions of war were readily made, or they turned with a strange facility to improvising gunboats and blockade runners. Within a year or two the people of the North showed the most bitter hatred of the South and everything Southern, and in the South women sold their hair for the common cause, and sent their gold and silver ornaments to the Government to be converted into implements of war. Such results could hardly have been the outcome of a hasty decision on either side. The long-nursed dislike of the people of each section now became a consuming hatred; it was a mighty struggle for the mastery of the Government which had been founded in 1787-89, for the control of the vast territory which composed the heart of North America. One party or the other must be vanquished, one section or the other must become a second Ireland.