United States

Geographical position, resources and population of the USA
The term "United States", when used in the geographical sense, is the contiguous United States, the state of Alaska, the island state of Hawaii, the five insular territories of Puerto Rico, Northern Mariana Islands, U.S. Virgin Islands, Guam, and American Samoa, and minor outlying possessions.^[1] The United States shares land borders with Canada and Mexico and maritime borders with Russia, Cuba, and the Bahamas in addition to Canada and Mexico. The northern border of the United States with Canada is the world's longest bi-national land border.
By total area (water as well as land), the United States is either slightly larger or smaller than the People's Republic of China, making it the world's third or fourth largest country. China and the United States are smaller than Russia and Canada in total area, but are larger than Brazil. By land area only (exclusive of waters), the United States is the world's third largest country, after Russia and China, with Canada in fourth. Whether the US or China is the third largest country by total area depends on two factors: (1) The validity of China's claim on Aksai Chin and Trans-Karakoram Tract. Both these territories are also claimed by India, so are not counted; and (2) How US calculates its own surface area. Since the initial publishing of the World Factbook, the CIA has updated the total area of United States a number of times.
The United States shares land borders with Canada (to the north) and Mexico (to the south), and a territorial water border with Russia in the northwest, and two territorial water borders in the southeast between Florida and Cuba, and Florida and the Bahamas. The contiguous forty-eight states are otherwise bounded by the Pacific Ocean on the west, the Atlantic Ocean on the east, and the Gulf of Mexico to the southeast. Alaska borders the Pacific Ocean to the south and southwest, the Bering Strait to the west, and the Arctic Ocean to the north, while Hawaii lies far to the southwest of the mainland in the Pacific Ocean.
The capital city, Washington, District of Columbia, is a federal district located on land donated by the state of Maryland. (Virginia had also donated land, but it was returned in 1849.) The United States also has overseas territories with varying levels of independence and organization: in the Caribbean the territories of Puerto Rico and the U.S. Virgin Islands, and in the Pacific the inhabited territories of Guam, American Samoa, and the Northern Mariana Islands, along with a number of uninhabited island territories. Some of the territories acquired were a part of United States imperialism, or to gain access to the east.
Natural resources are available in different parts of United States of America. It has huge deposits of natural gas, coal, uranium, copper, iron, phosphates, silver, gold, mercury, zinc, lead, bauxite, molybdenum, nickel, petroleum, potash, and many more. 

Easy availability of natural resources has helped the industrialization process of the United States to a great extent. The huge variety of natural resources contributes a substantial share of the revenue of the US federal government. The ready availability and abundance of natural resources also provide the nation with a comparative advantage in the global financial markets. 

Due to the non-renewable nature of fossil fuels like coal, natural gas, and petroleum, the use of renewable sources of energy has gained substantial popularity in United States in recent times. The federal and state governments of United States have put stress on conservation of natural resources. 

Increased dependence on fossil fuels has been an issue of major concern for the federal government of the United States. The unfavorable climatic changes resulting from it have adversely affected the marine living resources of US. Release of hazardous wastes into the sea water also stands in the way of conservation of natural resources. 

Natural Resources Council of America takes a number of initiatives for maintaining sustainability of country’s resources. The council also honors most effective innovation in the field of natural resources with the Academy Awards of Conservation. Preservation of natural resources also helps to maintain ecological landscape of the United States of America. 
The United States is the third most populous country in the world with an estimated population of 328,285,992 as of January 12, 2019.^[1][3]
The United States Census Bureau shows a population increase of 0.75% for the twelve-month period ending in July 2012. Though high by industrialized country standards, this is below the world average annual rate of 1.1%.^[4] The total fertility rate in the United States estimated for 2017 is 1.77 children per woman,^[5][6] which is below the replacement fertility rate of approximately 2.1.
The American population almost quadrupled during the 20th century—at a growth rate of about 1.3% a year—from about 76 million in 1900 to 281 million in 2000. It is estimated to have reached the 200 million mark in 1967, and the 300 million mark on October 17, 2006.^[7][8]Population growth is fastest among minorities as a whole, and according to the Census Bureau's estimation for 2012, 50.4% of American children under the age of 1 belonged to racial and ethnic minority groups.^[9]
White people constitute the majority of the U.S. population, with a total of about 245,532,000 or 77.7% of the population as of 2013. Non-Hispanic whites make up 62.6% of the country's population. The non-Hispanic white population of the US is expected to fall below 50% by 2045.^[10]
Hispanic and Latino Americans accounted for 48% of the national population growth of 2.9 million between July 1, 2005, and July 1, 2006.^[11] Immigrants and their U.S.-born descendants are expected to provide most of the U.S. population gains in the decades ahead.^[12]
The Census Bureau projects a U.S. population of 417 million in 2060, a 38% increase from 2007 (301.3 million),^[13] and the United Nations estimates the U.S. population will be 402 million in 2050, an increase of 32% from 2007.^[14] In an official census report, it was reported that 54.4% (2,150,926 out of 3,953,593) of births in 2010 were non-Hispanic white. This represents an increase of 0.3% compared to the previous year, which was 54.1%.
The median age of the total population is 38.1 years; the male median age is 36.8 years; the female median age is 39.4 years.
The population is distributed by age as follows:

• 
  0–14 years: 18.62% (male 31,255,995/female 29,919,938)
  
• 
  15–24 years: 13.12% (male 22,213,952/female 21,137,826)
  
• 
  25–54 years: 39.29% (male 64,528,673/female 64,334,499)
  
• 
  55–64 years: 12.94% (male 20,357,880/female 21,821,976)
  
• 
  65 years and over: 16.03% (male 22,678,235/female 28,376,817)
  

Sex ratios:

• 
  0–14 years: 1.04 male/female
  
• 
  15–24 years: 1.05 male/female
  
• 
  25–54 years: 1 male/female
  
• 
  55–64 years: 0.93 male/female
  
• 
  65 years and over: 0.79 male/female
  
• 
  Total population: 0.97 male/female