Ken and Ric Burns' THE CIVIL WAR, like it or not, influences documentary makers even now, because it was so successful that people realized that a documentary could reach and be enjoyed by the general public. It's a mixed blessing, because for years after it aired, filmmakers either intentionally copied his style, or were forced to do cheap imitations.
Ken was able to make history, covering times when there is very little visual documentation, come alive for people, and supplements his work with a lot of outreach.
(Currently, for THE WAR, he's put together kits to teach people how to interview their own relatives about their memories of WWII.)
Although I'm more of a fan of Ric's films, I think Ken, along with D.A. Pennebaker, Frederick Wiseman, Barbara Kopple and yes, Michael Moore, have had a huge influence on documentary filmmakers.