i think it depends on which state you are in, some have 17 as the age of consenet? meanwhile in canada, the current age of consent is 16, raised by the harper conservatives over a decade ago, it used to be 14. however, according to law and order:svu, if you are an american who travel to canada just to have sex with a 16 year old, even if she or he is legal in canada and your home state, you can still get nailed under sex tourism laws.
Canada