On June 2, Halleck telegraphed that if Rosecrans was unwilling to move, some of his troops would be sent to Mississippi to reinforce Grant, who by then was besieging Vicksburg, but was potentially threatened by the army of Joseph E. Johnston in his rear. Rosecrans sent a questionnaire to his corps and division commanders in the hopes of documenting support for his position—that Bragg had so far detached no significant forces to Johnston in Mississippi, that advancing the Army of the Cumberland would do nothing to prevent any such transfer, and that any immediate advance was not a good idea. Fifteen of the seventeen senior generals supported most of Rosecrans's positions and the counsel against advancing was unanimous. The only dissenter was the newly assigned chief of staff, Brig. Gen. James A. Garfield, who recommended an immediate advance. On June 16, Halleck wired a blunt message: "Is it your intention to make an immediate movement forward? A definite answer, yes or no, is required." Rosecrans responded to this ultimatum: "If immediate means tonight or tomorrow, no. If it means as soon as all things are ready, say five days, yes." Seven days later, early in the morning of June 24, Rosecrans reported that the Army of the Cumberland had begun to move against Bragg.