For ages and ages!
This is one of the stories you will find in the literature of science, of how, along with North America, South America, Europe, Asia, Africa, and Australia—have I left out any?—I came to land and brought your geography with me.
I remember hearing a pretty young lady say, once upon a time:
"There," said she, "I'm through with geography forever!"
You see, although she had passed with marks around 90, she still had the idea that geography is a book. You and I know, of course, that the real geography isn't a book at all. It's the world itself.
PUTTING THE CONTINENTS ON THE GLOBE
But there was a time when there was no land. It was all water, and the continents were lifted into their places, much as you model a continent in making a relief map; they were sketched out and then filled in. North America, for example. First of all up came that mass in the northeast in what is now Canada; the Laurentian Highlands, as they are called in your geography. They rose very, very slowly, you understand, only a few feet in a thousand years; for Nature has all the time there is and never hurries. These highlands (they are really granite mountains worn down), along with the other rock formations of our continent, are supposed to be the oldest land on the earth. The continents of Europe and the rest were born later. So you see Columbus didn't discover the New World at all; he really came from the New World and discovered the Old!
Next after the highlands north of the St. Lawrence up came the tops of the mountains you see running along the eastern coast, what we now call the Appalachians. Then the Rocky Mountains began to raise their heads and looked eastward toward their brother mountains across a great mediterranean sea, the bottom of which is now the Mississippi Valley. Mediterranean means "middle of the land."
HOW YOUR GEOGRAPHY ROSE OUT OF THE SEA