United Space of America

"Angus Deayton: There's also been a lawsuit revolving around the Pathfinder. [...] NASA have been sued by a couple of Yemeni men, because they claim they own Mars. They were left it by ancient ancestors.

[beat]

Martin Clunes: Well, it's better than the Americans just assuming it's theirs..."

- Have I Got News for You: The Official Pirate Video

This trope is about the tendency in works of science fiction to show the default form of human government to be an American-style republic. Such settings will (generally) have American standards regarding cultural norms, rights, and freedoms (with the occasional strange addition or subtraction, just to show that we aren't dealing with modern day Earth). Sometimes the cultural supremacy of the United States over all other human or alien "nations" is explicitly declared, while other times it's shown with a bit more subtlety.

In either case, most people, space stations, ships, planets, settlements, and so on will not only have names in English, but they'll also have names that are recognizably American. The Federation will be ruled by an elected President, there will be a Congress-like legislature, and so on. Even the military will use a ranking system based on American military ranks.

On the other hand, this can be kind of justified: the United States was established as a federal system, with protections for the rights of its constituent states combined with elements of direct representation of the people in the central government. Any democratic world government not established by conquest would likely take quite a similar form, with the currently-sovereign states surrendering only part of their power and retaining control of a significant portion of their government. The only really fishy thing about having an American-style government for all humanity is the direct election of an executive President: presidential systems, while they have their benefits, are hard to maintain, requiring a certain peculiar mix of national characteristics to really work well. A parliamentary government is rather more likely...which just shifts the style of government from the US to Canada or Australia.

See Space Romans for another culture that often is ~Recycled IN SPACE!~ See America Takes Over the World for when the world is run by the United States of America itself.

Anime and Manga

 * The Free Planets Alliance in Legend of the Galactic Heroes clearly invokes the USA (right down to the English lyrics of the anthem), to the point that they might as well be called "Space Americans" At the same time, however, it's revealed to be an increasingly dysfunctional democracy wracked by corruption. By the time the series begins, the efforts of a few good men like Yang Wen-li and the threat posed by their Space German enemies are pretty much the only things effectively holding them together.

Film

 * The Fifth Element has the President of the Federated Territories, of which Earth, specifically New York, appears to be merely the capital city. This is possibly meant to reference the United Nations.
 * The Star Wars prequels feature shades of this; though individual senators pick the head of state, there are representatives and senators, collectively known as the Senate, though it is more in line with the earlier Articles of Confederation with a fairly weak central government and very strong individual "state" governments. A major plot point is that at the time of the films the central government doesn't even have a standing army, relying instead on the semi-independent Jedi.
 * More of a Rome thing with first a senate ruling, then an emperor who gained his power due to war.
 * In Aliens it is clear that the United States is still a superpower and has colonized several planets. When contact is lost with LV-426 the United States Colonial Marine Corps is sent to investigate.

Literature

 * Mostly averted in Honor Harrington, though the People's Republic of Haven does have similarities to the United States and the European Union that start to show through more as the series develops. The Restored Republic of Haven, once it loses the French Revolutionary theme, is actually a federal government where the structure of the government is an appointed US style cabinet.
 * The Solarian League is probably a closer approximation to the (ante-bellum) USA - about to go through its equivalent of the American Civil War.
 * In The Stars, Like Dust by Isaac Asimov, the book revolves around a document that can destroy the tyranny of the empire known as, well, the Tyranni. At the end, when the characters read the document for the first time, it turns out to be a text of the United States Constitution.
 * The very concept of the Bio of a Space Tyrant series by Piers Anthony is that every planet in the world is, sociopolitically, a ~Recycled IN SPACE!~ version of some continent or region on Earth. For instance, the United States took the northern hemisphere of Jupiter--the largest planet in the solar system--to colonize and make into the image of the old Earthly United States.
 * Andrey Livadny does this in his The History of the Galaxy books with the Confederacy of Suns, which has an elected president. Not much else is known about the politics of the Confederacy. Each planet also has its own government, although everyone is subject to Confederate laws. Before the Confederacy, there was the Earth Alliance, which seems to be between this and The Empire with their treatment of the colonies and brutal suppression of any resistance. The Space Navy ranks are still Russian, though, with the addition of the "Galact" prefix.
 * Mikhail Akhmanov's Arrivals From the Dark series has this first with the USC (United States and Canada), which has military forces in space, along with Russia (with whom they are good friends) and European Union (which seems more unified than today). All three powers deliberately keep the other nations grounded, including China. In later novels, the Earth Federation is the official government of humanity, although it is unclear if the nation-states still exist as governing bodies.
 * It should be noted that the author specifically mentions that the ranks in the Space Navy are based on the British and American models, even though the books are Russian.

Live Action TV

 * Star Trek TOS: The United Federation of Planets was basically the United States IN SPACE! Bonus points for having the Klingons played as the counterpart for the Soviet Union and the Romulans act at least a little like Communist China. One of the most prominent is the use of "USS" as a ship registry.
 * In the first few episodes the Enterprise was explicitly stated to be a United States vessel and the Federation wasn't mentioned; this was retconned early in the first season but the USS registry was already established.
 * Which episodes were those? Early on in TOS "USS" was said to stand for "United SPACE Ship", not "United STATES Ship".
 * Of course, run a little checklist with Quentyn Quinn, Space Ranger and you may reach a slightly different conclusion: In Space.
 * In Battlestar Galactica Reimagined, the Twelve Colonies of Kobol needed only one more colony to be guilty of cultural copyright infringement; it mixes the United Space of America with the Twelve Tribes of Israel and Ancient Grome IN SPACE!.
 * On the other hand, Caprica in, well, Caprica has a Prime Minister (despite the prevalence of American Accents) and refers to "Ministers" (indicating parliamentary government). That, and the fact that racism is directed towards foreigners (especially Taurons) rather than a subgroup of native Capricans, suggests comparisons to Britain, especially '50s Britain. The Colonies as a whole had no unified government until the Cylon war forced them to, and as a result it is hinted on occasion that the Colonial Military has more influence and power than modern American-style systems.
 * Sea Quest DSV: The U.E.O., despite claiming to have a U.N.-like mandate, certainly acts like the United States.
 * Then you have Macronesia in Season 3, which is in a Cold War-like state with UEO. They have a charismatic president, who doesn't shy from using illegal means to achieve his goals.
 * Firefly: complete with a Wild West motif and allusions to The American Civil War. On the other hand, there's extensive use of Chinese culture, with lots of use of Chinese-style dress, writing system, and language. The backstory explains the whole mess as the result of an alliance between the US and China.
 * It's also mentioned that the areas surrounding the American-settled capital world (in contrast to the other Chinese one) match this trope much' more closely.
 * Red Dwarf seems to be set in an American-style society with a few British influences. The justice system uses American legal jargon, the brig is styled after American prisons and officially there isn't a Floor 13 (which is a mostly American tradition). Spacelanes are on the right and in the alternate history from Tikka to Ride, Russia's victory in the space race resulted in Red Dwarf not being built.
 * Of course, it averts this at times as well. For example, in Back To Earth, Rimmer claims that one day he'll be First Lord Of The Star Fleet, presumably making the Space Corps a British organisation.
 * Babylon 5 does this by having the Earth Alliance be created by the major powers in the wake of First Contact to replace the UN. It took a war to bring some of the smaller countries in (or something like that), and San Diego got nuked by terrorists as a result. The President and Vice President are directly elected, but the various countries of Earth still exist, subject to Earth Alliance law. 'Earthdome' is however in Geneva, home of many League of Nations entities, not San Fransisco or New York.
 * We should note, however, that the establishment of a dictatorship was pure Machtergreifung and Gleichschaltung, with President Clark in the role of...well...you know....
 * Mostly averted in Andromeda with the Systems Commonwealth, primarily because it was not founded by humans but by the Vedrans, transforming what used to be the Vedran Empire into a government that shares similarities with a republic, although it is ruled by a triumvirate (possibly based on the British Commonwealth). The High Guard ranks are still suspiciously human, although in this case the fact that humans are one of the most prolific member races probably has something to do with it. The Commonwealth also has the Lancer Corps (whose ranks are mostly American), which are typical Space Marines and have a rivalry with the High Guard, similar to the rivalry between the branches of the military in the US (and probably most other countries).

Tabletop Games

 * The Terran Confederation of the early Traveller timeline as detailed in the volume Interstellar Wars, though it's close enough to being Twenty Minutes Into the Future that the Confederation might literally be a futuristic offshoot of the United States.
 * The Second and Third Imperiums that succeed the Confederation, naturally, are aversions.
 * Played with in the backstory of Battletech. There were plenty of colonies that traced their culture and ancestry to the United States of America, but they were also the closest colonies to Terra due to America's technological edge allowing them to get there first. When the unification wars started, they were also the first to be burned to the ground leaving the Successor States with very few "North American" survivors. The South Americans went on to help form the Free Worlds League.
 * Subverted in the RPG Traveller:2300 (which, confusingly, is not in the same franchise universe as Traveller, despite being published by the same company [Game Developers Workshop]; later on it was renamed simply "2300AD"). The "universe" of Traveller:2300 was developed by the game designers actually gaming out future history. In that game, it was France that dominated, and so emerged as the major interstellar power.

Video Games

 * The Codex for Mass Effect claims that the countries are still all divvied up more or less as they are now (save that the European Union looks to be all one country now, and Mexico, Canada and Carribean Islands joined the US to form the United North American States). The Systems Alliance, however, is the face of humanity as far as the other species of the galaxy are concerned, having started as a token organization to organize the various government's efforts into space before being granted extraterrestrial rights to all human interests in space.
 * One of the planet descriptions describes a conflict between the United North American States, European Union, and People's Federation of China over colonization rights. It calls them coalitions, so they may be more like regional alliances.
 * The I.S.A of Killzone is essentially America in space fighting an amalgamation of every totalitarian regime ever in space. Unfortunately, Evil Is Cool combined with the I.S.A's astonishing bland-ness inspires major Rooting for the Empire.
 * Disturbingly and importantly averted by The UNSC. As of the Human-Covenant War, the UNSC now control all government on all human planets. Basically, it's a military run empire. Previously, it was much more America-like, but it still differed, and the UNSC still had alot of power. Even more importantly, a secret group of smart AIs have been running the show for centuries, meaning that it's been a secret dictatorship (which would take such measures as nuking a human colony if it served their purposes).
 * Before the Human-Covenant War the UNSC was the Unified Earth Government's military and exploratory agency, tasked with protecting the colonies and expanding into the galaxy, with the colonies' civilian government being assigned to local representatives and the Colonial Administration Authority. By the end of the war the colonies have been so utterly devastated and the resources necessary to wage total war had resulted in the UNSC assuming de facto control of both the UEG and the CAA.
 * The Terran Confederation from Wing Commander is the largest and most important human government in the setting, consisting of over 700 star systems. It is a representative democracy headed by an elected president, and the chief legislative body is the Confederation Senate which is based in Washington D.C. Additionally, the armed forces of the Terran Confederation are made up of four branches: Army, Navy, Marines, and Space Forces. Basically, the Terran Confederation is a 27th century version of the United States of America.
 * The Gallente Federation in Eve Online, despite being descended from the French, is very conspicuously based on the USA. It has an elected President, a Senate and a Supreme Court, a love of freedom, democracy and political equality, a highly free-wheeling and galactically influential pop culture, and even a large wave of immigration from a country on their border.

Western Animation

 * Futurama does this in a big way. Technically the Earth has unified into one country that just seems to be called "Earth", but all aspects of the government that aren't just random jokes are clearly based on the present-day United States. The president of Earth is Richard Nixon's disembodied head, the Earthican flag is even the exact same as the American flag, except with a globe in place of the stars, Washington DC is the capital and the US Constitution is still the ruling document (with some minor changes in the 22nd amendment wording that allowed Nixon to claim there Aint No Rule to prevent his reelection).
 * There's also the Democratic Order of Planets, of which Earth is a member, and which appears to be responsible for military "protection" of Earth and allied worlds. When Zapp Brannigan accidentally destroyed the new DOOP Headquarters in the Neutral Zone, the DOOP council moved back to their old HQ in Weehawken, NJ.
 * Wait, so they thought a debris cloud in hard vacuum was worse than New Jersey?!
 * The Simpsons episode "The Secret War of Lisa Simpson" has a fimstrip that ends with the phrase "The moon belongs to America, and anxiously awaits the arrival of our astro-men. Will you be among them?"