The United States sprang into the greatest war the world has ever known, a war in which men and machines and resources were being consumed in enormous quantities, with an army numbering, all told, only 212,000. The first necessity was to create, train and equip an army that would, at the earliest possible moment, number millions of men and thousands of officers. American sentiment had always been strongly opposed to the principle of compulsory military service and the only attempt the country had ever made to use the draft system, during the Civil War, had caused dissatisfaction, disturbance and riot in civil life and in its military results had been practically a failure. Through many days of discussion in Congress and throughout the country the question was threshed out, while enlistments to the number of over 800,000 were swelling the ranks of the Regular Army, National Guard and Reserve Corps organizations. In the end, there was general agreement that only the draft system could furnish the enormous numbers of men required and draw them from civil life with democratic justice and with due regard to social and economic interests. As a large number of foreign born citizens had come here to escape the compulsory military service of their native countries, there were many grave fears of the result and it was even expected that in centers of foreign population there would be riotous demonstrations of protest. But those who were thus apprehensive had not rightly estimated the intelligence, the democracy and the Americanism of the whole citizenship of the country, foreign as well as native born. The success of the Selective Service Law, enacted by Congress on May 18, 1917, was as spectacular as it was complete. The entire machinery of registration, compilation and report was organized and made ready for operation in the eighteen days following the enactment of the law and was wholly manned by volunteer service from civil life. On June 5th, in a single day, without disturbance or protest anywhere, the entire male population of the country between the ages of twenty-one and thirty, inclusive, went to the registration booths and registered for military service, and practically all the returns were in Washington within twenty-four hours. Two subsequent registrations of young men who had reached the age of twenty-one after June 5th brought the number of registrants up to a little more than 10,000,000 men.