"Aroused by the statements of Gov. Horatio Seymour and other Democratic leaders that the conscription act was unconstitutional, the populace was incited to action. Laborers, mostly Irish-Americans, made up the bulk of a tremendous mob that overpowered the police and militia, attacked and seized the Second Ave. armory containing rifles and guns, and set fire to buildings. Abolitionists and blacks were especially singled out for attack. Many blacks were beaten to death, and a black orphanage was burned, leaving hundreds of children homeless. Business ceased, and robbing and looting flourished. Since the conscription provision that allowed the rich to buy exemption was especially resented, the Tammany city government voted to pay the necessary $300 for anyone who might be drafted. Meanwhile, New York troops (including the famous 7th Regiment, which had been sent to the front for the Gettysburg campaign) were rushed back, and with the aid of the police, militia, naval forces, and cadets from West Point, they succeeded in restoring order."

http://www.encyclopedia.com/doc/1E1-draftrio.html

I thought I had read somewhere that veteran troops who had fought at Gettysburg were rushed in to stop the rioting. It appears they had help from several quarters. Stan