The United States of America is the world’s third largest country in size. Located in North America, the country is bordered on the west by the Pacific Ocean and to the east by the Atlantic Ocean. On the northern side is Canada and the southern side is Mexico. The United States of America consists of 50 states, 5 territories and 1 district (Washington D.C.). The United States is a federal republic and it is set up by the Constitution. The White House is the official residence of the President in the capital city of Washington, D.C. America has been a nation of immigrants. The population is diverse and from ethnic backgrounds. Majority of the population in the United States come from European countries and a small group of people is African-American.