The United States of America, often referred to as the United States, is a federal constitutional republic, spread over an area of 3,537,438.44 sq mi, in North America. It is flanked by the Pacific ocean and the Atlantic ocean on either sides, and bordered by Canada and Mexico in the north and south, respectively. The United States is the 3rd largest country in the world in terms of both, the land area and population. Washington D.C. is the capital district of the nation, while New York City is the largest city. For administrative purposes, the United States is divided into 50 states; each of which shares sovereignty with the federal government. Political Division of the United States of America Of the 50 federal states, which form the United States, 48 are contiguous states. The 2 exceptions are Alaska and Hawaii, which lie to the northwest of the continent and in the mid-Pacific, respectively. Alaska is the largest state in terms of area, while California has the distinction of being the most populous state in the US. The first thirteen states of the United States were constituted following the rebellion of the thirteen colonies in 1776. Since then, the US Congress has exercised its power to add several new states to the Union; the last of which was the state of Hawaii. (The US Supreme court considers secession unconstitutional; even though there is no explicit mention of the same in the Constitution.) The possibility of adding new states to the Union cannot be ruled out. Of the few names that are being discussed, Puerto Rico is most likely to become the 51st state of America. As of now though, the number of states in USA is 50 -- and not 48, 49 or 51 as many people believe. The list of 50 states given below has been arranged in the order in which they were admitted to the Union, starting with Delaware on December 7, 1787, to Hawaii on August 21, 1959. Having said that, it is important to note that the first 13 states had already become the member states after they declared their independence, and formed the United States of America in 1776. In this list, however, these 13 states have been enlisted in accordance to the day on which they ratified the United States Constitution. Until 1959 there were 48 states in America, but the admission of Alaska and Hawaii that year brought the number to 50. Other than these 50 states, there are some areas which are dependent on the United States for administration. These include the American Samoa, Puerto Rico, Virgin Islands, Navassa Island, and the Northern Mariana Islands. Even though the number of states is 50, only the 9 most populous states in the country house more than half of the total population.