His documentary on the 2nd world war is very good too, though it's very different from the civil war doc. Naturally of course it's a different war and a different era, but he did things with those differences that were kind of interesting. The 19th century being the 19th century, people were attuned to language in a different way than in the 20th century, so frequently in the civil war doc you heard these greatly articulate letters being read. American English in the 20th century was much more laconic, plus you could still (at that point) interview many veterans, so what we got instead of letters were these emotion-packed interviews. You could see where people who could not always say what they thought, saw, and felt were still shaken by it deep down.
Plus the Burns WW2 doc covers aspects of the war other WW2 documentaries don't.