To become a citizen of The United States comes with a number of rights, privileges and responsibilities. First and foremost a citizen is entitled to the voting rights, serving in public office, holding a US passport, equal protection under the law, among many others. These valuable rights can be obtained through 3 different methods. The first of which is being born in the United States also called Jus Soli. The second is being born to at least one US person anywhere in the world called Jus Sanguinis. The third is naturalization which non-US citizens may apply for.
The first method to citizenship is to be born within the United States or one of its territories. This became a law post-civil war with the 14th amendment to the constitution. This guaranteed citizenship to ex slaves and American Indians who were born within the US boundaries. Full rights and privileges are passed to the child with access to all benefits and responsibilities of every other citizen.
The second method is children born to a citizen of the US. This dates to the Naturalization Act of 1790. The law helps protects and guarantee citizenship to children of US citizens born outside of the US. This includes but is not limited to, foreign diplomats, US military, and citizens living abroad. If one parent is a citizen, qualifications must be met like a minimum amount of time for the parent to have lived within the US. If both parents are citizens, then any time spent in the US allows for citizenship to be passed along.
The third method is to apply for a process known as citizenship through naturalization. This process is available to those who do not qualify for the aforementioned options. Several standards must be met in order to apply for this. The individual must be a legal resident of The US and present at least half of the time. This option is available for adults over the age of 18. The individual will be tested on their ability to comprehend basic English, US history and politics. A good moral character must be demonstrated. Finally, they individual must demonstrate their allegiance to The United States and the Constitution.
There are some other options that affect a smaller number of individuals like internationally adopted children by US citizens. However, the result of each avenue to citizenship is the same. Once a US citizens, there is a guarantee of the principles set out in the Declaration of Independence and Constitution. There are also responsibilities that are obligatory like following the laws of the country and being held accountable when they are not followed, and even serving in the US military when needed.