Can one go to canada with a green card or US passport or needs a visa?

Question

Can one go to canada with a green card or US passport or needs a visa?

Answer 1

if your an American from the USA??  all you need is a drivers licence and birth certificate or a passport to gain admittance to Canada.  No visa  requirements.  

When returning to USA if by land again drivers licence and birth certificate (if before 2009)  and if by air you now need passport definately to return

Answer 2

If you are an American citizen you  can drive into Canada without a passport, but should take an original birth certificate and state ID card.  If you are flying into Canada then you will need a passport.

American citizens do not need a visa to visit Canada.