Here's for new york state...

http://pweb.netcom.com/~brlevine/ny.txt

Interesting that although the law reads, essentially, that everything is illegal, the case law (toward the bottom of the page) which establishes how laws are to be interpreted and sets prescedence, allowed that the person's possession of a sheathed, fixed blade knife, visible on his person, with no intent to use the knife in an unlawful manner,was not in itself unlawful. so by that argument in NYS, you could wear your sgian dubh legally ("OK officer, but you see that case law allows...")