All of them. A passport is needed always when you are leaving the country.
You will need a passport to travel between borders and to return to the US. You will not need a visa for most countries, but they will ask how long you intend to stay and why you are traveling.
Yes.
No. As long as you are traveling to or from other US States you do not need to bring your passport
No. They only need a passport when they leave the US.
everyone flying into the US needs a passport
Yes you do
That depends on where you're coming from, and your country of citizenship. If you're a US citizen and flying from Los Angeles, it's about as difficult to enter Hawaii as it is to enter Santa Monica. Remember that Hawaii is one of the US of A.
If you are a US citizen you don't need a passport to fly within the USA (for example from Kansas City to Chicago), but you will need some form of official photo ID such as a drivers licence. If you are not a US citizen you will also need photo ID and a passport is best for this.
== == No, you do not need a passport. You do need a valid ID though. Any state issued ID is good with a photo, like a drivers liscense.
none. he need a passport
passport, drivers licence, proof of age, birth certificate but usually photo id is required
Puerto Rico, and other US territories like the Virgin Islands.