Walt Whitman supported the Mexican-American War. He justified his support of the war with the concept of manifest destiny. This was the idea that the USA was destined to stretch from coast to coast on the North American continent. Dominated by Anglo-Saxons, the USA had a mission to spread civilization and institutions across the American continent. Whitman believed that it was America's duty to rid Mexico off its misery, inefficiency, her burlesque against freedom and superstition.