5. On the 19th of April, when the Massachusetts volunteers were passing through Baltimore, they were fired upon by the citizens and three men killed. This was the first bloodshed of the war. On the day previous, a body of Confederate soldiers captured the armory of the United States at Harper's Ferry. On the 20th of the month another company obtained possession of the great navy yard at Norfolk. The property thus captured amounted to fully ten millions of dollars. On the 3d of May the President issued a call for eighty-three thousand soldiers to serve for three years or during the war. General Winfield Scott was made commander-in-chief. War ships were sent to blockade the Southern ports. In the seceded States there was boundless activity. The Southern Congress adjourned from Montgomery, to meet on the 20th of July, at Richmond. There Mr. Davis and the officers of his cabinet had assembled to direct the affairs of the government. So stood the antagonistic powers in the beginning of June, 1861. It is appropriate to look briefly into THE CAUSES of the conflict. CHAPTER XLV. CAUSES OF THE CIVIL WAR. [Sidenote: Meaning of the Constitution.] The most general cause of the civil war in the United States was _the different construction put upon the Constitution by the people of the North and of the South_. A difference of opinion existed as to how that instrument was to be understood. One party held that the Union of the States is indissoluble; that the States are subordinate to the central government; that the acts of Congress are binding on the States; and that all attempts at nullification and disunion are disloyal and treasonable. The other party held that the national Constitution is a compact between sovereign States; that for certain reasons the Union may be dissolved; that the sovereignty of the nation belongs to the individual States; that a State may annul an act of Congress; that the highest allegiance of the citizen is due to his own State; and that nullification and disunion are justifiable and honorable. 2. This question struck into the very heart of the government. It threatened to undo the whole civil structure of the United States. In the earlier history of the country the doctrine of State sovereignty was most advocated in New England. Afterwards the people of that section passed over to the advocacy of national sovereignty, while the people of the South took up the doctrine of State rights. As early as 1831 the right of nullifying an act of Congress was openly advocated in South Carolina. Thus it happened that the belief in State sovereignty became more prevalent in the South than in the North. [Sidenote: Systems of Labor.]