To answer your question, "sort of."
Crappy answer, right? I know.
Unfortunately, the U.S. Supreme court has been perfectly happy to leave knife laws to local lawmakers.
Depending on where you live, most knife laws only refer to concealed
knives. So, if you wear it on your belt, in plain sight, it's legal -- regardless of blade length. So, 12" Bowie under your coat = illegal. On your belt = legal. Go figure.
Just be sure you check your local laws before wearing the pigsticker to the supermarket!