The United States of America (USA), commonly referred to as the United States (US), America, or simply the States, is a federal republic consisting of 50 states, 16 territories, and a federal district. The 48 contiguous states and the federal district of Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The country also has five populated and nine unpopulated territories in the Pacific and the Caribbean. At 3.79 million square miles (9.83 million km2) in total and with around 316 million people, the United States is the fourth-largest country by total area and third largest by population. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The geography and climate of the United States is also extremely diverse, and it is home to a wide variety of wildlife.
Paleo-indians migrated from Asia to what is now the US mainland around 15,000 years ago, with European colonization beginning in the 16th century. The United States emerged from 13 British colonies located along the Atlantic seaboard. Disputes between Great Britain and these colonies led to the American Revolution. On July 4, 1776, delegates from the 13 colonies unanimously issued the Declaration of Independence. The ensuing war ended in 1783 with the recognition of independence of the United States from the Kingdom of Great Britain, and was the first successful war of independence against a European colonial empire. The current Constitution was adopted on September 17, 1787. The first 10 amendments, collectively named the Bill of Rights, were ratified in 1791 and guarantee many fundamental civil rights and freedoms.
Military organisation is the structuring of the armed forces of a state so as to offer military capability required by the national defence policy. In some countries paramilitary forces are included in a nation's armed forces. Armed forces that are not a part of military or paramilitary organisations, such as insurgent forces, often mimic military organizations, or use ad hoc structures.
Military organisation is hierarchical. The use of formalised ranks in a hierarchical structure came into widespread use with the Roman Army. In modern times, executive control, management and administration of military organisations is typically undertaken by the government through a government department within the structure of public administration, often known as a Department of Defense, Department of War, or Ministry of Defence. These in turn manage Armed Services that themselves command combat, combat support and service support formations and units.
Active duty refers to a full-time occupation as part of a military force, as opposed to reserve duty. In Great Britain and the Commonwealth the equivalent term is active service.
Military science is the theory, method, and practice of producing military capability in a manner consistent with national defense policy.]citation needed[ Military science serves to identify the strategic, political, economic, psychological, social, operational, technological, and tactical elements necessary to sustain relative advantage of military force; and to increase the likelihood and favorable outcomes of victory in peace or during a war. Military scientists include theorists, researchers, experimental scientists, applied scientists, designers, engineers, test technicians, and other military personnel.
Military personnel obtain weapons, equipment and training to achieve specific strategic goals. Military science is also used to establish enemy capability as part of technical intelligence.
Higher education in the United States refers to the process of students continuing their education beyond high school, and includes a variety of institutions of higher education. Strong research and funding have helped make United States colleges and universities among the world's most prestigious, making them particularly attractive to international students, professors and researchers in the pursuit of academic excellence. According to the Shanghai Jiao Tong University's Academic Ranking of World Universities, more than 30 of the highest-ranked 45 institutions are in the United States (as measured by awards and research output). Public universities, private universities, liberal arts colleges, and community colleges all have a significant role in higher education in the United States.
Recent high visibility issues include greater use of the Internet (such as Massive open online courses), competency based education, cutbacks in state spending, and rapidly rising tuition and burdensome student loans
Colonel Barbara Janet Bishop, USMC, was Director of Women Marines from January 1964 until her retirement in August 1969. Prior to this assignment, she completed a tour of duty in Naples, Italy, as Military Secretary to the Commander in Chief, Allied Forces, Southern Europe.