Caller ID Says Doraville Georgia.  When I answered, they hung up.  When I tried to call it back, as soon as the line picked up it was like a number was being redialed...then silence

no messages left - received several calls

This is some kind of Vietnam vets organization selling various things or taking straight donations.

They are using an older automated-dialing system. If you call (and don't get a busy signal), let it ring and ring until it picks up (it could take several minutes). You will then hear the system dialing a number. If you start saying, "Hello, hello" over and over, someone will come online thinking they have (auto) dialed someone else and that someone has answered the call. They will ask for Mr. or Mrs. whoever.

This is when you can have a little fun with them because they don't know who you are and you can be prepared ahead of time. Use your imagination!

It can make for some very funny recordings!

Yes thanks for the information.
They asked me for donation to the veterans and when I replied that I am not going to do that through them he said, "you don't want to know what my feelings are about immigration" and hung up. For a second I was not sure what he meant then I thought of my accent, I am not originally from the US even though I lived here most of my life.
So for you out there with any foreign background, you may want to consider NOT donating to this prejudice and questionable fundraising group. You can always donate to this cause by calling the official legitimate agencies...

... and by the way, the guy had a British accent. I guess British don's considered themselves foreigners here ....