A Vast and Rich Land To understand the United States, you have to first start with the land. The United States occupies the core of the North American continent. While the American people have had something to do with the creation of their wealth, they could not have accomplished what they did without the American land. America built its industrial base on and still produces enormous quantities of its own raw materials, from oil to timber to iron ore. The vast flat American heartland, and the fertile valleys of California, are among the most productive agricultural areas on earth. From the country's earliest days the three coasts (Atlantic, Pacific and Gulf of Mexico), the Great Lakes, and the substantial river systems have provided key natural transportation networks. The United States is divided into 50 states, each having separate state governments, flags, laws and traditions. Puerto Rico, the U.S. Virgin Islands, Guam and American Samoa are also part of the United States, each with a special status as a dependency or territory. dependency or territory.