Switchblades are in fact legal to posses in Oregon, although to carry it with you, in order for it to be legal, it CANNOT be concealed (this means it has to be visible). If you are under 18, be careful, it's illegal to carry.
NO
no
No they are not
no they are not legal in minnisota but they are in Wisconsin
No they're not.
Yes
No
Yes but not switchblades, i think
I believe they are legal, but if I were you I would do more research.
no they are not, they are considered switchblades
As of September 1st 2013, yes.
Yes switchblade's are illegal in Colorado as is any knife that is assisted opening such as a gravity knife like the butterfly knife or is assisted with a spring or lever. This is not completely true. A knife that is "spring assisted" is legal as long as you have to have direct contact with the blade to open it (such as those that have a small nub on the back of the blade, or those that have a thumb nub), while "spring loaded" or "automatic" (as stated above) are illegal. Many knife makers such as Kershaw have spring "assisted" knives that are completely legal in Colorado.