http://canada.usembassy.gov/visas/i...-canadians.html

Canadian visitors are generally granted a stay in the U.S. for up to six months at the time of entry. Requests to extend or adjust a stay must be made prior to expiry to the U.S. Citizenship and Immigration Service.

http://canada.usembassy.gov/visas.html

Note: Canadian citizens do not require a visa to enter the United States directly from Canada for the purposes of visiting or studying.

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