Shirley Jones' Son Ryan Cassidy Releases Children's Book on Day with James Cagney: 'He Was Bigger Than Life'

Ryan Cassidy

Few people can say they've spent the day being babysat by an Academy Award-winning actor. But Ryan Cassidy is one of those lucky few — and has written a book reflecting on the impact of that special day.

As the youngest son of The Partridge Family's matriarch Shirley Jones and Tony-award-winning actor Jack Cassidy and brother of teen heartthrob David Cassidy, Ryan, 57, had an extraordinary childhood growing up in Hollywood. However, one of the standout moments in the now-author's life was one afternoon he spent with the iconic actor James Cagney, who died in 1986.

He documented the experience in his new children's book James Cagney Was My Babysitter, which also features a foreword and afterword from Jones, 88, who was friends and worked with the late actor.

"I'm very fortunate to have had a wonderful career in show business and to have worked with some brilliant actors," Jones wrote in the foreword. "Among the many movies and television shows I was privileged to do, the opportunity to work with the legendary James Cagney was a very special moment for me."

Goodknight Books

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In an exclusive interview with PEOPLE, Ryan shares more about why he felt this was an important story to tell now, 50 years later.

"I would meet a lot of people that would come up to me through the years and say, 'I grew up watching your brother. I grew up watching your mother, and you must have really met a lot of interesting people in your life,'" Ryan tells PEOPLE. "And I have met a lot of interesting people, a lot of fun people, a lot of incredibly talented people, and they've often said, you ought to write a book about it."

The person that stood to him the most, though, was Cagney. The day he stayed with the actor, Ryan was 7 years old and a quiet boy with an avid imagination.

Cagney fostered Ryan's curiosity and even drew him a signed picture of a dancing elf — which hangs in the author's living room to this day.

"I think the fact that he was this bigger-than-life movie star that had already sort of done his work, and he was semi-retired at this point, and he saw my mother and father were going through a separation, and I think he felt a need to see where I was at with everything," Ryan says.

He adds, "He made me feel really comfortable, and he made me feel like I could express myself in a way and tell him what my interests were. He didn't make it about him that day."

Ryan Cassidy

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Growing up in Hollywood in the 1970s, Ryan was no stranger to actors. He shares how his peers at school would always tell him how much they loved his mom and brothers, and he was "so proud" to hear it.

However, at the end of the day, Ryan created his own lane, working primarily behind the scenes on TV and movie sets rather than in front of the camera like many in his immediate family.

"I would say I'm proud of my family," Ryan says. "I'm my own person, and I am where I'm at in life because I have learned through whatever I went through to get to where I'm at. And I'm proud of who I am, but I'm not my family. I'm my own person."

To this day, as drives by the lot, Ryan sees the old set of The Partridge Family where he used to play as a child and ask to drive the infamous bus (though he was never given the keys).

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Raised in a creative family, Ryan had no shortage of mentors to inspire him, including Cagney, with whom he continued to cross paths as he got older. He hopes this book will inspire children to seek the same mentorship and those who influence them in a positive way.

"Young people can create a parallel to somebody that they grew up with or knew or met, and they can realize that we all can have these experiences at different times and decades in our life," Ryan says.

"And the importance of them is that we look sometimes for mentors that we don't know, and we find them, and they have even influenced us more in a positive way. So I believe that the message in it for kids is don't be afraid to share your experiences and write them down of people that you met that meant something to you," he continues.

Ryan stresses that while the book is aimed for a young audience, people of all ages can take something away from the story. While children can be inspired, fans of older cinema can reminisce on Cagney and Jones and their work.

In all he does, Ryan says, he aims to spread positivity and a sweet message. This book is just the latest addition to Ryan's work spreading love, inspiration and hope.

"I try to live with giving back a positive message in every aspect of my life," Ryan says. "And I'm at a point in my life where I have enough understanding and wisdom to be able to give to somebody else that I hope that they can carry with them, and it betters their life in some way and gives them a different perspective that they didn't have."

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James Cagney Was My Babysitter will hit bookstores on March 14.