VA: The main thing is, no autos. No blade length limit that I know of, but if you are going to drive around the beltway in Northern VA (which goes through DC and MD) you have to consider that, should you get in an accident in those areas.
Not that it will affect you, but FYI D.C. laws are 3" limit on folders and no fixed blades. But police in our area don't just stop people and search them unless they are acting outrageous or committing crime. They don't look for pocket clips on ordinary people, in my experience.