He also landed guest spots in early television series such as Dick Tracy, Racket Squad, Fireside Theatre, and Adventures of Superman.
[7] Chamberlain was often cast in film noirs where he specialized in playing nervous types, like the frightened bookkeeper Freddie Bauer in Force of Evil (1948).
He was first brought to the attention of Congressional investigators in 1940 when Rena Vale named him to the Special Committee on Un-American Activities, chaired by Congressman Martin Dies.
[8] Vale told the Dies Committee that in 1938 the Federal Theater Project's L.A. chapter was a front for the Communist Party USA, and that Chamberlain was an active member in it.
Not much is known about how Chamberlain earned a living as a blacklistee over the next two decades, but he eventually landed the role of Patch Riley in the 1974 TV movie A Touch of the Poet, based on the Eugene O'Neill play.
[11] He returned to the Broadway stage in 1976 with a minor part, and understudy assignments, in Larry Gelbart's long-running comedy, Sly Fox.