The United States established a draft which would bring in many workers to the military. As the war prevented immigration from Europe even before the U.S. entered the war, major companies had begun to recruit black workers from the South to fill demand. When white workers went on strike in April 1917 at the Aluminum Ore Company, the employer hired blacks as strikebreakers. The American Steel Company also recruited blacks. They were available in part during this period because the U.S. Army initially rejected many black volunteers in the years before an integrated military. This was also the period of resentment on both sides and the arrival of new workers created fears for job security at a time of union organizing and labor unrest, and raised social tensions. At a large labor meeting of white workers held in City Hall on May 28, men also traded rumors of fraternizing between black men and white women. An inflammatory speaker said, “East St. Louis must remain a white man’s town.” Three thousand ethnic white men left the meeting and headed as a mob for downtown, where they randomly attacked black men on the street. The Illinois governor called in National Guard to prevent further rioting, but rumors circulated that blacks were planning an organized retaliation and tensions remained high.