Diverse and Varied. No country on earth has a population as diverse and a culture as varied as the United States. It is this very diversity that makes American life as complicated as it is. On the one hand, the United States is a nation. On the other hand, even after four centuries, that nation is still a great experiment. The United States occupies a continent and has many varied regions. Over the course of several centuries, immigrants from all over the world came to the United States and brought their own cultures and traditions. The tradition of immigration continues today, creating vital new American communities. The blending of these traditions gives the United States its great strength as a nation. The same mixture creates challenges and problems.