When Miss Dennison (who is part of the plot to kill President Grant) is holding Arte at gunpoint, he praises her performance in the play Our Country Cousins. The name of her play's a reference c to the play Abraham Lincoln was attending at the Ford Theater the evening he was assassinated.
Final television work for actor Wendell Corey, who died later that year on November 8, 1968, age 54.
The third season ended prematurely with the February 23, 1968 broadcast of "The Night of the Death-Maker" after Robert Conrad was seriously injured on January 24, 1968 during filming of the 24th show, which was never completed. The actor, who enjoyed doing his own stunts, was injured after leaping from a balcony to grab on to a big chandelier, but slipped and landed on his head some 15 feet below the lighting fixture. As a result, Conrad suffered a double skull fracture, followed by weeks of hospitalization and a long convalescence that shut down production of the series. Originally, twenty-six shows were to be produced during the season prior to Conrad's injury.
The pre-opening credits scene had a man cranking a Piano on a make shift cart.
It is not an organ with a (monkey-less) grinder.