Following its debut in 1963, young audiences tuned into The Patty Duke Show each week to see the hilarious antics of twin cousins: Patty and Cathy.
As the theme song explained, Patty was the Brooklyn Heights born and bred teen who loved dancing to rock 'n' roll and eating junk food. On the other hand, Cathy was more refined and preferred classical music and ballet.
Their clashing personalities were actually inspired by Patty Duke's own dueling moods, something producer and writer Sidney Sheldon observed when she came to spend time with his family while he developed the beloved show. Of course, those shifts in personality later made sense when the actress was diagnosed with bipolar disorder as an adult.
But that isn't the only fascinating fact about the charming show from the 1960s.
Take a look below for a walk down memory lane and learn even more about the iconic series.
Let us know in the comments if we missed your favorite fact about The Patty Duke Show and be sure to SHARE with your friends!
1. The Theme Song Might Sound Familiar
That's because it was performed by The Skip-Jacks, the same group who performed the equally catchy tune for the cartoon family, The Flintstones, starting in season 3.
2. Patty Broke Records With Her Young Age
She was already the youngest actress to receive an Academy Award for her role in The Miracle Worker just before the show's debut, but that reign ended when Tatum O'Neal won the same award at just 10 years old in 1973.
However, her title as the youngest actress to have her own self-titled TV show remains unchallenged.
3. They Filmed In NYC For More Than Authenticity
Though the series was based in Brooklyn Heights, that wasn't the only reason the production crew decided to film in the Big Apple.
Rather, it was because the state had more relaxed child labor laws and they were able to work Patty for more hours a day since she was playing two roles at once. After she turned 18, they moved production to California despite her wishes to remain on the east coast.
4. There Was A Reason The Cousins Looked Alike
The idea of "twin cousins" is a bit of a stretch, but the producers explained it by having William Schallert, who plays Patty's father Martin, also pull double roles as his twin brother, Cathy's father.
They both added a triplet to the mix when William again played another brother, Jed, and Patty played his daughter Betsy.
5. They Tried To Get Bette Davis To Guest Star
When the legendary actress starred in a double role of her own in 1964's Dead Ringer, the show approached her for a tongue-in-cheek appearance. But Bette reportedly demanded too much money and several perks, so they rescinded the offer.
6. Patty Had A Hit Song During The Series
Despite not using her musical talents on the theme song, the young actress had her own Top 10 hit in 1965 with "Don't Just Stand There."
7. Patty's Body Double Became A Soap Star
In scenes where the cousins were together with one's head turned away from the camera, actress Rita Walter (then going by her maiden name McLaughlin) was standing in place with the alternate girl's hairstyle.
Later, she would spend 11 years with her face finally in full view as a regular on the daytime soap As the World Turns, from 1970-81.
8. Richard Was Actually Much Older Than Patty
Though the character was supposed to be the same age as Patty, the actor playing her boyfriend, Eddie Applegate, was actually 11 years her senior.
9. Three Cast Members Died In 2016
It was a year that took a lot of our most beloved entertainment icons. But for fans of the series, it was especially difficult to see not just Patty herself pass on March 29, but also to say goodbye to William Schallert on May 8 and Eddie Applegate on October 17.
All three reunited in a PSA for Social Security like the one shown above with Patty and William. Paul O'Keefe, who played Patty's younger brother, Ross, is now the only surviving member of the show.
10. Color TVs Ended The Series
With the popularity of color television sets growing in the mid-1960s, the network decided to focus their funds on non-black and white shows.
Though the series was maintaining good ratings, it would have been more expensive to switch over to color rather than start fresh with a whole new show in its place.
11. Patty Grew Close To Her On-Screen Dad
The actress told the Los Angeles Times that her fictional "poppo," as she called him on the series, became a surrogate for her own father, and that she and William remained close even after the series ended.
"He's the dad I never got to spend time with," she explained. "The family we created [on] the show was very much a family. That was my safety zone."
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