How can you become a us citizen at birth?

Answer 1

There are lots of ways. If at least one of the parents is a US citizen, they can go to the nearest US consulate/embassy and see if their children become citizens too. It's not always automatic- if one parent is a US citizen and one isn't, it becomes a little complicated. If both parents are US citizens, it's pretty much automatic.

Otherwise, it generally involves moving to the US and doing something to become a citizen. For example, if a person moves here legally, lives here for a period of time (usually 5 years but sometimes 3, like if the person marries a US citizen), they can apply for "naturalization", where they'll become a citizen. Alternatively, the person can join the US Military, and as part of their contract, become a citizen (it has to be written in the contract, unless the US is at war).

Another way is through "derivative" citizenship. When a person naturalizes as a US citizen, if they have children who are under 18 when they naturalize, those children become US citizens too, assuming they meet a few minor requirements (such as having a "green card"). Since 1983, this also applies to adopted children. For children born prior to February 1983, derivative citizenship was a little more complicated- both parents had to naturalize (or the one who didn't had to be dead or divorced without custody), and adopted children couldn't apply.

This isn't an all-inclusive list, but it's a quick list of the most common ways of going about it.

Answer 2

if you were born there, or if you take a citizenship test there.