Ms. Backus was 93 and died at UCLA Medical Center.
Known as Henrietta Kaye before she was Henny Backus, she was born in Brooklyn and appeared as a showgirl in the Broadway revue, Earl Carroll's Vanities.
According to the trade paper, during the Depression, Ms. Backus belonged to an acting group formed by the WPA that included Orson Welles, John Houseman and Joseph Cotton. Internet Broadway Database reports that she was in the cast of Chrysalis, a 1932 Broadway play that featured Humphrey Bogart.
After marrying Backus, she lived in California with her husband and appeared in films and on TV. She was Cora Dithers in the TV series "Blondie," with her husband playing Dagwood Bumstead's boss, Mr. Dithers.
With her husband, she co-authored books about Hollywood, including "What Are You Doing After the Orgy?," "Only When I Laugh" and "Forgive Us Our Digressions." According to The Los Angeles Times, after her husband died of pneumonia in 1989, she wrote "Care for the Caretaker," about taking care of seriously ill loved ones.