The intensity of Confederate resistance compelled Union commanders to accept this notion, while the influx of black refugees into Yankee camps helped to force a decision. In 1861 Ulysses S. Grant believed that the Union should keep hands off slavery if a quick peace and rapid reconciliation was desired. Grant's experiences as a field commander are illustrative of this process, suggesting the interaction between the progress of the war effort, the escalation of Southern resistance, and the transformation of war aims to encompass emancipation. From war's beginning Grant realized that at the core of the dispute was the institution of slavery. Grant let slip his growing antislavery convictions on other occasions. During the fall of 1861 his forces sparred with Polk's units, and the two armies met once in a pitched battle at Belmont, Missouri. Nor was Grant willing to tolerate actions which exceeded the bounds of conventional warfare.