Depends on who you ask. Technically I think it was outlawed during the Reconstruction period after the Civil War, but I'd have to look it up to be certain.
Why is everyone so obsessed with appearances rather than personality these days?
Ignorance! A friend of mine's son has a rebel flag tattoo; he wanted to join the military. The recruiter asked him about his Rebel flag. Mic replied, "That's not a rebel flag that's a Confederate flag!"