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.
The term "black people" is an everyday English-language phrase, often used in North America to refer to Americans and Canadians of Sub-Saharan African descent. Outside North America, the term "black people", or close translations of it, is also used in other socially based systems of racial classification, or of ethnicity for persons who are perceived to be dark-skinned relative to other "racial" groups – or else who are defined as belonging to a "black" ethnicity in the country.
Different societies, such as Australia, Brazil, the United Kingdom, the United States, and South Africa apply differing criteria regarding who is classified as "black", and these have also varied over time. Often social variables, such as class and socio-economic status, affect classification, so that relatively dark-skinned people can be classified as white if they fulfill other social criteria of "whiteness," and relatively light-skinned people can be classified as black if they fulfill the social criteria for "blackness" in a particular setting. As a result, in North America, for example, the term "black people" is not necessarily an indicator of skin color but of a socially based racial classification related to being African American, with a family history related to institutionalized slavery. In other regions, such as Australia and Melanesia, the term "black" has been applied to, and used by, populations with a very different history.
A social issue (also called a social problem or a social situation) is an issue that relates to society's perception of a person's personal lives. Different cultures have different perceptions and what may be "normal" behavior in one society may be a significant social issue in another society. Social issues are distinguished from economic issues. Some issues have both social and economic aspects, such as immigration. There are also issues that don't fall into either category, such as wars.
Thomas Paine, in Rights of Man and Common Sense, addresses man's duty to "allow the same rights to others as we allow ourselves". The failure to do so causes the birth of a social issue.
Hospitality is the relationship between the guest and the host, or the act or practice of being hospitable. This includes the reception and entertainment of guests, visitors, or strangers.