Harpo was advised by his doctors not to do the show, because he was coming off heart surgery.
Though it looks like one continuous shot, it is actually several shots spliced together, because Harpo kept changing the routine.
Lucille Ball and Harpo Marx had previously appeared in the Marx Brothers film Room Service (1938) for RKO. By this time, what was formerly RKO Studios was now owned by Lucy and Desi Arnaz and renamed Desilu Studios.
Harpo Marx was previously mentioned in The Black Wig (1954), in which Fred jokes that people thought that Ethel was Marx when she had a poodle haircut the previous year.