If we will suppose a civilized, maritime people to have planted colonies, in the remote past, along the headlands and shores of the Gulf of Mexico, spreading thence, in time, to the tablelands of Mexico and to the plains and mountains of New Mexico and Colorado, what would be more natural than that these adventurous navigators, passing around the shores of the Gulf, should, sooner or later, discover the mouth of the Mississippi River; and what more certain than that they would enter it, explore it, and plant colonies along its shores, wherever they found a fertile soil and a salubrious climate. Their outlying provinces would penetrate even into regions where the severity of the climate would prevent great density of population or development of civilization. The results we have presupposed are precisely those which we find to have existed at one time in the Mississippi Valley. The Mound Builders of the United States were pre-eminently a river people. Their densest settlements and greatest works were near the Mississippi and its tributaries. Says Foster ("Prehistoric Races," p. 110), "The navigable streams were the great highways of the Mound Builders." Mr. Fontaine claims ("How the World was Peopled") that this ancient people constructed "levees" to control and utilize the bayous of the Mississippi for the purpose of agriculture and commerce. The Yazoo River is called Yazoo-okhinnah--the River of Ancient Ruins. "There is no evidence that they had reached the Atlantic coast; no authentic remains of the Mound Builders are found in the New England States, nor even in the State of New York." ("North Americans of Antiquity," p. 28.) This would indicate that the civilization of this people advanced up the Mississippi River and spread out over its tributaries, but did not cross the Alleghany {sic} Mountains. They reached, however, far up the Missouri and Yellowstone rivers, and thence into Oregon. The head-waters of the Missouri became one of their great centres of population; but their chief sites were upon the Mississippi and Ohio rivers. In Wisconsin we find the northern central limit of their work; they seem to have occupied the southern counties of the State, and the western shores of Lake Michigan. Their circular mounds are found in Minnesota and Iowa, and some very large ones in Dakota. Illinois and Indiana were densely populated by them: it is believed that the vital centre of their colonies was near the junction of the Ohio and Mississippi rivers.