sentences:  In 1967 he played a littering tourist in the "Lassie" episode "Lassie's Litter Bit", an iconic episode which earned a trip for Lassie to the White House to shake hands with then First Lady "Ladybird" Johnson who had used the famous collie in her Keep America Beautiful Campaign.Rockwell was a founding member of the California Artists Radio Theatre.He played standard leads in a couple of anti-Communist-era features, including Republic's "The Red Menace" (1949), in which he is cast as a returning veteran of World War II, who is duped by communists.