The strength of the national sentiment and of the tradition of freedom was very powerfully exhibited in the strain of the great Civil War (1861-65) which maintained at a great cost the threatened unity of the republic, and brought about the emancipation of the negro slaves. And the Civil War produced in Abraham Lincoln a national hero, and an exponent of the national character and ideals, worthy to be set beside Washington. The America of Lincoln manifestly stood for Liberty and Justice, the fundamental ideals of Western civilisation. But in this great moulding tradition of freedom there was one dubious and narrowing element. Accustomed to regard herself as having achieved liberty by shaking off her connection with the Old World, America was tempted to think of this liberty as something peculiar to herself, something which the 'effete monarchies' of the Old World did not, and could not, fully understand or share, something which exempted her from responsibility for the non-American world, and from the duty of aiding and defending liberty beyond her own limits. In the abounding prosperity of this fortunate land, liberty was apt to be too readily identified merely with the opportunity of securing material prosperity, and the love of liberty was apt to become, what indeed it too often is everywhere, a purely self-regarding emotion. The distance of the republic from Europe and its controversies, its economic self-sufficiency, its apparent security against all attack, fostered and strengthened this feeling. While the peoples of the Old World strove with agony and travail towards freedom and justice, or wrestled with the task of sharing their own civilisation with the backward races of the globe, the echo of their strivings penetrated but faintly into the mind of America, like the noises of the street dimly heard through the shuttered windows of a warmed and lighted room. To the citizens of the Middle West and the Far West, especially, busy as they were with the development of vast untapped resources, the affairs of the outer world necessarily appeared remote and insignificant. Even their newspapers told them little about these far-off events. Naturally it appeared that the function of the republic in the progress of the world was to till its own garden, and to afford a haven of refuge to the oppressed and impoverished who poured in from all lands; and this idea was strengthened by the great number of immigrants who were driven to the New World by the failure of the successive European revolutions of the nineteenth century, and by the oppressive tyranny of the Habsburg monarchy and the Russian despots.