The United States of America is situated in the central portion of North America with its fifty states. It is a federal constitutional republic. It is one of the largest countries in the world and the population is increasing as a result of immigration from various countries. The economy of the county is the strongest. After the World War II, the Unites States became the first country to possess nuclear weapons and emerged as a super power. The country is a permanent member of the United Nations Security Council. Just like the population, USA has the most diverse geography and climate. The country is well advanced in science and technology