Because I was at Gettysburg today and there it was. In all it’s glory.
OK, they had a small, small display with the note to ask at the desk for availability. So I asked and I slapped the $129 they asked for down on the table.
Surreal. I’ve checked fairly faithfully on Amazon in the past and it was never there. Is it possible that the National Park Service has it first?
I think it was just released on DVD, as it is the 10th anniversary of it’s 1st airing, so they decided to give it the DVD treatment, digital remastering, extra interviews and other HOO-HAAS!!
It was indeed released just a couple of weeks ago, to conincide with both the anniversary and with PBS’s re-airing of the documentary. I’m stoked. It’s on my Christmas list. 
It was released a couple of weeks ago, and if you had checked at Best Buy, you could have saved $30.
Pah, you DVD-bound plebeans. It was released on laserdisc nearly ten years ago. <gloat>