Rivers are natural, and therefore, also the easiest and cheapest roads. Especially in countries of great area, as the United States, Russia and the Ukraine, the importance of rivers as roadways is very great. Rivers connect the nations. The Dniester and the Dnieper connected the Ukraine with the sea, with the highly-cultured Constantinople, with the entire Mediterranean and Oriental world of culture. The Dnieper, thru its much branched water-web, [230]connected the Ukraine directly with Poland and White Russia, and indirectly with the Baltic Sea and Northern Europe. Even today, altho the canals connecting the Dnieper with the Vistula, Niemen, and Dvina are entirely neglected, the Dnieper River plays a very significant part as a great vein of traffic connecting different lands, peoples and producing regions. It may become more important still if it is made accessible to sea vessels and connects two distant seas. In the Cossack period a considerable portion of the Ukrainians became a river people. The life and work of the Zaporog Sich depended entirely upon the Dnieper River. It protected, fed and clothed them. So strongly were the Zaporogs bound to the Dnieper, so necessary did the great river become to them, that all attempts to found new Zaporog centers on other rivers simply failed. We need not wonder, then, that the Dnieper is celebrated in all the Cossack songs as a sacred possession of the nation. Closely connected with the character of rivers as roadways, is their importance as the directing lines of the movements of races. The history of the Ukraine tells us how the ancient Kingdom of Kiev penetrated toward the south along the Dnieper, and how the Kingdom of Halich reached the delta of the Danube by way of the Dniester and Prut. Most likely the first expansion of the Ukrainians proceeded along the Dniester, Boh and Dnieper, southward. At the time of the great shifts of the Ukrainian southeast border, the advance of the Ukrainians was always directed southeast, their retreat always northwest. The history of the 16th Century shows plainly how the first pioneers of the new colonization movement—the Cossacks—pushed along the Dnieper, toward the southeast, into the steppe region. Altho it is a commonplace, yet it may be established without doubt that the whole Ukrainian nation took its way southeast along the Ukrainian rivers. To this [231]day the national territory of the Ukraine is advancing irresistibly in that direction.