ADMITTING NEW STATES TO THE MAP
Wisconsin, into which I moved from the Laurentian Highlands in later years, was on the lower end of a long, thin tongue of rock reaching out from these highlands to the southwest. While Wisconsin went on growing, the Alleghanies came up and brought some Middle Atlantic geography with them. Up with all these early settler mountains came, in the course of time, the beginnings of neighbor States. All these big, barren rocks (as they were then), rising and ever rising, age after age, spread more surface to the sun. And the sun, and the wind, and the frost, followed by the lowest forms of plant life—the Adams of the vegetable world—gradually worked the surface of the rock into soil; and so, as we may say, got ready for the spring plowing.
LANDS THE SEA HAS SWALLOWED
Parts of the continents as they used to be but which are now beneath the waters are here shown. Compare this with the globe map in your geography. It is estimated that there are 10,000,000 square miles of this land. You'll hear more about this swallowing habit of the sea in [Chagter X]; but, as you will learn, there's nothing to be frightened about.
By this constant rising and building on of the soil the foundations of our States grew out toward one another in order, according to the constitution of things, "to form a more perfect union." The United States, at a time which, we may say, corresponds to "The Expansion Period" in your school history, grew southward from Wisconsin and westward from the Appalachians until they made continuous land; and there was your Ohio and Indiana and the rest of the North Central group. Below, toward the south, were more big stone islands here and there, the first sketches or blockings out of the Southern States. Florida seems to have been added later, as a final touch; an afterthought, as one of my Wisconsin neighbors puts it. And it was much enlarged by those remarkable little world builders, the corals. Mexico and Central America, of course, are a part of the Rocky Mountain system.
From Gilbert and Brigham's "An Introduction to Physical Geography." By permission of D. Appleton and Company
BUT WON'T WE GO UNDER AGAIN?
These little people of the sea-floor furnish one of the most assuring evidences we have that although the continents rose out of the sea, they will never go under the sea again. These are shell creatures found in the slime dredged from the bottom of the deepest parts of the sea. The shells of creatures that live near shore are found in abundance in our rocks, but these types are found only in the deepest seas. So, since the deep down-wrinklings of the earth that make the sea-basins have never risen, it is probable they never will; and consequently that the up-wrinkles—the continents—will continue to stay above the waters.