Indians (U.S.) American Indians to attack U.S. settlements on the western frontier. War hawks in the U.S. called for an invasion of Canada to punish the British Empire and to lessen the threat to American interests represented by the Native Americans. At the same time, the American states were becoming crowded, and there was a growing attitude—later described by the phrase Manifest Destiny—that the United States was destined to control all of the North American continent. American hawks