United States in the context of "List of countries by date of recognition of the United States"

A metropolitan area or metro is a region consisting of a densely populated urban agglomeration and its surrounding territories which share industries, commercial areas, transport network, infrastructure and housing. A metropolitan area usually comprises multiple principal cities, jurisdictions and municipalities: neighborhoods, townships, boroughs, cities, towns, exurbs, suburbs, counties, districts and even states and nations in areas like the eurodistricts. As social, economic and political institutions have changed, metropolitan areas have become key economic and political regions.

In the United States, metropolitan areas are delineated around the core of a core based statistical area, which is defined as an urban area and includes central and outlying counties. In other countries metropolitan areas are sometimes anchored by one central city such as the Paris metropolitan area (Paris). In other cases, metropolitan areas contain multiple centers of equal or close to equal importance, especially in the United States; for example, the Dallas–Fort Worth metropolitan area has eight principal cities. The Islamabad–Rawalpindi metropolitan area in Pakistan, the Rhine-Ruhr in Germany, and the Randstad in The Netherlands are other examples.

A declaration of war is a formal act by which one state announces existing or impending war activity against another. The declaration is a performative speech act (or the public signing of a document) by an authorized party of a national government, in order to create a state of war between two or more states.

The legality of who is competent to declare war varies between nations and forms of government. In many nations, that power is given to the head of state or sovereign. In other cases, something short of a full declaration of war, such as a letter of marque or a covert operation, may authorise war-like acts by privateers or mercenaries. The official international protocol for declaring war was defined in the Hague Convention (III) of 1907 on the Opening of Hostilities.

Ratification is a principal's legal confirmation of an act of its agent. In international law, ratification is the process by which a state declares its consent to be bound to a treaty. In the case of bilateral treaties, ratification is usually accomplished by exchanging the requisite instruments, and in the case of multilateral treaties, the usual procedure is for the depositary to collect the ratifications of all states, keeping all parties informed of the situation.

The institution of ratification grants states the necessary time-frame to seek the required approval for the treaty on the domestic level and to enact the necessary legislation to give domestic effect to that treaty. The term applies to private contract law, international treaties, and constitutions in federal states such as the United States and Canada. The term is also used in parliamentary procedure in deliberative assemblies.

A jury is a sworn body of people (jurors) convened to hear evidence, make findings of fact, and render an impartial verdict officially submitted to them by a court, or to set a penalty or judgment. Most trial juries are "petit juries", and consist of up to 15 people. A larger jury known as a grand jury has been used to investigate potential crimes and render indictments against suspects, and consists of between 16 and 23 jurors.

The jury system developed in England during the Middle Ages and is a hallmark of the English common law system. Juries are commonly used in countries whose legal systems derive from the British Empire, such as the United Kingdom, the United States, Canada, Australia, and Ireland. They are not used in most other countries, whose legal systems are based upon European civil law or Islamic sharia law, although their use has been spreading. Instead, typically guilt is determined by a single person, usually a professional judge. Civil law systems that do not use juries may use lay judges instead.

Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundaries with the Pacific Ocean to the west, the Caribbean Sea to the southeast, and the Gulf of Mexico to the east. Mexico covers 1,972,550 km (761,610 sq mi), and is the thirteenth-largest country in the world by land area. With a population exceeding 130 million, Mexico is the tenth-most populous country in the world and is home to the largest number of native Spanish speakers. Mexico City is the capital and largest city, which ranks among the most populous metropolitan areas in the world.

Human presence in Mexico dates back to at least 8,000 BC. Mesoamerica, considered a cradle of civilization, was home to numerous advanced societies, including the Olmecs, Maya, Zapotecs, Teotihuacan civilization, and Purépecha. Spanish colonization began in 1521 with an alliance that defeated the Aztec Empire, establishing the colony of New Spain with its capital at Tenochtitlan, now Mexico City. New Spain became a major center of the transoceanic economy during the Age of Discovery, fueled by silver mining and its position as a hub between Europe and Asia. This gave rise to one of the largest multiracial populations in the world. The Peninsular War led to the 1810–1821 Mexican War of Independence, which ended Peninsular rule and led to the creation of the First Mexican Empire, which quickly collapsed into the short-lived First Mexican Republic. In 1848, Mexico lost nearly half its territory to the American invasion. Liberal reforms set in the Constitution of 1857 led to civil war and French intervention, culminating in the establishment of the Second Mexican Empire under Emperor Maximilian I of Austria, who was overthrown by Republican forces led by Benito Juárez. The late 19th century saw the long dictatorship of Porfirio Díaz, whose modernization policies came at the cost of severe social unrest. The 1910–1920 Mexican Revolution led to the overthrow of Díaz and the adoption of the 1917 Constitution. Mexico experienced rapid industrialization and economic growth in the 1940s–1970s, amidst electoral fraud, the Tlatelolco massacre, and economic crises. The late 20th century saw a shift towards neoliberalism, marked by the signing of the North American Free Trade Agreement (NAFTA) in 1994, amidst unrest in Chiapas.

Samurai (侍) were members of the warrior class who served as retainers to lords in Japan prior to the Meiji era. Samurai existed from the late 12th century until their abolition in the late 1870s during the Meiji era. They were originally provincial warriors who served the Kuge and imperial court in the late 12th century.

In 1853, the United States forced Japan to open its borders to foreign trade under the threat of military action. Fearing an eventual invasion, the Japanese abandoned feudalism for capitalism so that they could industrialize and build a modern army. The adoption of modern firearms rendered the traditional weapons of the samurai obsolete, and as firearms are easy enough for peasant conscripts to learn, Japan had no more need for a specialized warrior caste. By 1876 the special rights and privileges of the samurai had all been abolished.

A county seat is an administrative center, seat of government, or capital city of a county or civil parish. The term is in use in six countries: Canada, China, Hungary, Romania, Taiwan, and the United States. An equivalent term, shire town, is used in the U.S. state of Vermont and in several other English-speaking jurisdictions.

Puerto Rico (abbreviated PR), officially the Commonwealth of Puerto Rico, is a self-governing Caribbean archipelago and island organized as an unincorporated territory of the United States under the designation of commonwealth. Located about 1,000 miles (1,600 km) southeast of Miami, Florida, between the Dominican Republic in the Greater Antilles and the U.S. Virgin Islands in the Lesser Antilles, it consists of the eponymous main island and numerous smaller islands, including Vieques, Culebra, and Mona. With approximately 3.2 million residents, it is divided into 78 municipalities, of which the most populous is the capital municipality of San Juan, followed by those within the San Juan metropolitan area. Spanish and English are the official languages of the government, though Spanish predominates.

Puerto Rico was settled by a succession of Amerindian peoples beginning 2,000 to 4,000 years ago; these included the Ortoiroid, Saladoid, and Taíno. It was claimed by Spain following the arrival of Christopher Columbus in 1493 and subsequently colonized by Juan Ponce de León in 1508. Puerto Rico was contested by other European powers into the 18th century but remained a Spanish possession for the next 400 years. The decline of the Indigenous population, followed by an influx of Spanish settlers, primarily from the Canary Islands and Andalusia, and African slaves vastly changed the cultural and demographic landscape of the archipelago. Within the Spanish Empire, Puerto Rico played a secondary but strategically significant role compared to larger and wealthier colonies like Peru and New Spain. By the late 19th century, a distinct Puerto Rican identity began to emerge, centered on a fusion of European, African, and Indigenous elements. In 1898, following the Spanish–American War, Puerto Rico was acquired by the United States.

A city centre, also known as an urban core, is the commercial, cultural and often the historical, political, and geographic heart of a city. The term "city centre" is primarily used in British English, and closely equivalent terms that exist in other languages, such as "centre-ville" in French, Stadtzentrum in German, or shìzhōngxīn (市中心) in Chinese. In the United States, the term "downtown" is generally used, though a few cities, like Philadelphia, use the term "Center City" or "City Center".

The World Factbook, also known as the CIA World Factbook, is a reference resource produced by the United States' Central Intelligence Agency (CIA) with almanac-style information about the countries of the world. The official print version is available from the Government Publishing Office. The Factbook is available in website and downloadable formats. It provides a two- to three-page summary of the demographics, geography, communications, government, economy, and military of 258 international entities, including U.S.-recognized countries, dependencies, and other areas in the world.

The World Factbook is prepared by the CIA for the use of U.S. government officials, and its style, format, coverage, and content are primarily designed to meet their requirements. It is also frequently used as a resource for academic research papers and news articles. As a work of the U.S. government, it is in the public domain in the United States.