He had a major role in founding the PBS network, and was influential in the career of documentary filmmaker
Ken Burns. Burns first met Chamberlin in 1985. He needed funding to complete his documentary about
Huey Long. He had heard that Chamberlin was a history buff and showed him a rough cut of the project. Chamberlin recognized Burns' talent, and had WETA (the PBS station in Washington DC) take the unusual step of covering the cost of finishing the film. WETA co-produced many of his subsequent documentaries, including
The Civil War (1990), which was a tough sell to underwriters because of its length and reliance on still photos.