North America is a vast continent, but the early explorers could not have known exactly how vast. From the very beginning, however, immigrants to this new land began to think in terms of taking control of the entire land mass, even after they discovered that the continent already was populated with indigenous people. Regardless, three hundred years of European colonization of the Americas set the stage for a period of rapid westward expansion that resulted in the United States extending its influence "from sea to shining sea" in just a few decades.
This process of American territorial expansion was driven by many forces, and many other factors had to fall into place to make it possible. Many obstacles had to be overcome, too, so the story is one of human endeavor, endurance, and devotion to duty; the process was accomplished at a great cost to others as well, so it is just as much a story of human arrogance and cruelty.
The resources used in this application come primarily from Wikipedia, the Free Encyclopedia. This resource, which "anyone can edit," sometimes raises controversy. People wonder how it can be very authoritative if "just anyone" can edit it, but it actually offers some advantages over the usual bound editions of encyclopedias we may be more accustomed to. First, it is free, which is a great advantage in itself. Another great advantage is that it can be corrected and updated on a constant basis. We may not realize it, but inaccurate information exists in many bound encyclopedias, and once the information is bound up between those covers, it is there for good. Thus, rather than being less accurate, many times Wikipedia is more accurate than the bound editions.
Still, it usually is not a good idea to take all of your information from only one source. Researchers should try to determine the truth of a situation from consulting many sources. An exception was made in this case for convenience, and to expose students to this fairly new resource, which has been available only since 2001.
Another great resource for those interested in geography is any of the aerial mapping Web sites available today. This application uses Google Maps Flash Earth, but there are many others. Both of these Web-based applications allow users to see the landforms and water courses as they would from above. The both allow users to zoom the view in or out and to click and drag the maps around to get the view users want. Google Maps allows users to select "Hybrid" mode, which superimposes highways, state boundaries, etc. onto an aerial photograph. The aerial photography used in Flash Earth, however, tends to be of a higher quality, and the user can manipulate it in more ways than with Google Maps. One thing to remember about Flash Earth is that it will come up the first time with a black box in the middle of the screen. You must click on this box to get a clear view of the scene below.