After 9/11 we had a few avenger turrets in various places (one was in the parking lot at the Navy annex where I used to work), those have since been removed.
I believe we also had a few surface launched AMRAAM (also called CLAWS or whatever the Norwegians call the system we sold to them) in places, I believe one was at Boling (sp?) AFB along 295. That is also gone.
The USSS (or a military unit that works with them) has some stingers, but in general, I believe we don't do fixed AAA or SAMs any more because supposedly the surveillance is sufficient to enable intercept by aircraft...or provide enough warning for USSS or whomever to break out a stinger.