Nearly 600,000 students from all over the world studied in the United States last year at both the undergraduate and graduate levels. It goes without saying that America offers very high quality post-secondary education. There are more than 4,000 public and private colleges, universities, and community colleges in the United States, including over 600 public four-year colleges and universities and over 1,650 private four-year colleges and universities. These traditional institutions enroll nearly 15 million students. In addition, over 6,000 non-collegiate post-secondary institutions offer specialized vocational and technical training.

Political System
The United States is the longest-surviving constitutional republic with the oldest written constitution in the world. Its government operates as a representative democracy through a congressional system under a set of powers specified by its Constitution. There are three levels of government: federal, state, and local. Officials at all three levels are either elected by voters in a secret ballot or appointed by other elected officials.

Technology
The United States is an influential country in scientific and technological research and the production of innovative technological products. During World War II, the U.S. was the first to develop the atomic bomb, ushering in the atomic age. During the beginning of the Cold War, the U.S. began successes in space science and technology, leading to a space race, which led to rapid advances in rocketry, weaponry, material science, computers, and many other areas, culminating in the first visit of a man to the moon, when Neil Armstrong stepped off of Apollo 11 in July 1969.

In the sciences, the United States has a large share of Nobel Prizes, especially in the fields of physiology and medicine. The National Institutes of Health, a focal point for biomedical research in the United States, has contributed to the completion of the Human Genome Project. The main governmental organization for aviation and space research is the National Aeronautics and Space Administration. Major corporations, such as Boeing and Lockheed Martin, also play an important role.

Economy
The U.S. has the largest and most technologically powerful economy in the world, with a per capita GDP of $46,000 (2007). In this market-oriented economy, private individuals and business firms make most of the decisions, and the federal and state governments buy needed goods and services predominantly in the private marketplace. U.S. business firms enjoy greater flexibility than their counterparts in Western Europe and Japan in decisions to expand capital plant, to lay off surplus workers, and to develop new products. At the same time, they face higher barriers to enter their rivals' home markets than foreign firms face entering U.S. markets. The merchandise trade deficit reached a record $847 billion in 2007. Long-term problems include inadequate investment in economic infrastructure, rapidly rising medical and pension costs of an aging population, sizable trade and budget deficits, and stagnation of family income in the lower economic groups. Together, these problems caused a marked reduction in the value and status of the dollar worldwide in 2007.

Health
The U.S. spends more on health care per capita than any other nation in the world. Yet, according to the Institute of Medicine of the National Academy of Sciences, the U.S. is the only wealthy, industrialized nation that does not have a universal health care system. United States health care is provided by a diverse array of individuals and legal entities. Individuals are offered inpatient and outpatient services by commercial, charitable, or governmental entities. The health care system is not fully publicly funded but contains a mix of public and private funding. A new poll released by the American Cancer Society and Trust for America's Health (TFAH) found that Americans ranked the flu epidemic, cancer and obesity as their leading health concerns. Life expectancy is relatively high (78 years) and infant mortality is high.

Society and Culture
There are many stories, positive and negative, about American people and many have preconceived ideas from films and television programs that they have seen. It's extremely difficult to categorize and describe 'American culture'. American society is extremely diverse and complex and should not be reduced to stereotypes. Important differences exist between geographical regions, between rural and urban areas, and between social classes. In addition, the presence of millions of immigrants who came to the United States from all corners of the world with their own culture and values adds even more variety and flavor to American life.