Coming to America

[Highhopesman]

How long can one person who is not an american citizen come into the US and stay before having to leave, or apply to be a citizen?

[NORMANTHEDOG]

tourists 90 days,others have to have some sort of visa.

[spudqueen]

As Norman said, 90 days http://www.usembassy.org.uk/rctour.html
but if you want to emigrate that is a totally different matter, and extremely hard
http://www.usembassy.org.uk/rctour.html

[spudqueen]

Sorry that second link should be
http://www.usembassy.org.uk/cons_new/visa/iv/i ndex.html

[dzug]

The answers given so far are only partially true, and assume the visa waiver scheme applies.

If the non-American citizen has a visa (eg B2 tourist visa) he will typically be admitted for 90 or possibly 180 days. Provided he applies before the end of that period, and can prove he is still a tourist and can support himself without working, that period can be extended for a further 90 or 180 days or whatever the Immigration Office decide is appropriate. The process can be repeated in theory until the visa expires (maximum 10 years from the date of issue) though in reality they would stop believing he was a tourist long before that and require him to leave the country before his final authority to stay expired.

[KARL]

All of the above answers are primarily based on UK citizens' circumstances. It is my understanding that in fact the period varies depending on which country issues the passport in question. The US has schemes in place whereby citizens of some countries can enter relatively freely, others are required to apply for a visa which, in some cases will be issued for a very limited period. The US has no diplomatic relations with ceretain countries and citizens of those may only be able to apply for visas through a third country's mission. For a few such countries the chances of obtaining a visa, and therefore of visiting the US legally, are very remote indeed.