Maria Testa’s father didn’t tell her much about his boyhood. Their family wasn’t the kind to sit around on a porch swing talking about the good old days. As it turns out, some of her father’s good old days weren’t so good.

His father regularly spent time in jail for gambling and brawling. When he was home, he caused only trouble for the boy, his mother and sisters.

But at least there was Joe DiMaggio. For a young Italian-American boy growing up with a father who spent more time in prison than at home, Joltin’ Joe loomed large.

“Joe DiMaggio was huge in those days,” said Testa, a Portland writer whose children’s book “Becoming Joe DiMaggio,” released by Candlewick Press in March, was inspired by her family’s stories. “He was the ultimate American hero. He was a solid influence, a force.”

The book recounts a young boy’s ongoing relationship with his immigrant grandfather Papa-Angelo (based on Testa’s great-grandfather) and their discussions about baseball and life. Divided into 24 vignettes, the book has a gentle, narrative style. Testa, who has written four books for children, calls it a “linear poetry collection.” But it is also a deeply American story about fatherhood, ethnic life, wartime, baseball and heroism.

“All of those ideas were in my head when I wrote the book,” said Testa, who studied sociology as an undergraduate at Brown University and went on to study family law at Yale University Law School. “First and foremost, I was exploring how I understood my father’s life. But I wouldn’t have written this book if I hadn’t done what I did academically.”

Still, says the writer, she found something personally galvanizing about the connection between her father and grandfather listening to baseball on the radio, and the powerful impact of a hero’s excellence and reliability – especially when that hero shares the same ethnic heritage.

It comes down to a triangle of respect and admiration that goes from grandfather to grandson to DiMaggio. Testa, a die-hard Yankees fan, inherited a love of baseball, but also a sense of the place it held in her own family ethos.

“My father loved his grandfather, and he talked about Joe DiMaggio in the

same way,” said Testa, who has two young sons. “Joe DiMaggio and his grandfather were linked in my father’s heart, you might say. When my father felt really great about something, he’d say: ‘I feel like Joe DiMaggio.’ So there was an emotional understanding about Joe DiMaggio that ran through our family.”

Because the father in Testa’s book is depicted as a ne’er-do-well, Joe DiMaggio takes on mythic proportions for the young boy central to the story. He looks to DiMaggio as a role model and decides to defy the odds of a neglectful childhood and become a doctor.

“For someone in my father’s circumstances, DiMaggio was an introduction to the notion of excellence,” said Testa.

Indeed, Testa’s father became a surgeon. He eventually went to Vietnam, was exposed to Agent Orange and, 15 years ago, died of complications from that exposure.

“Becoming Joe DiMaggio” is part of a developing trilogy in which Testa is exploring her father’s life. Next year, a new book called “Almost Forever,” based on her father’s year in Vietnam, will be released. She is currently writing the third book, which will be about the trauma a family endures when the father has been afflicted by the aftereffects of Agent Orange.

Testa writes the books for a general audience of young readers but knows her work may have particular appeal for pre-teen boys. However, her first book, “Some Kind of Pride,” is about 11-year-old Ruth who is a star shortstop that plays better than any of the boys but, because she is a girl, has no future in the major leagues. The book was awarded the Marguerite De Angeli Prize for elementary school readers, and has been optioned for film rights.

A native Rhode Islander, Testa moved to Maine to become a writer.

“If I stayed in southern New England or went to New York, I wouldn’t have worked on writing,” said Testa. “Maine has slowed me down and proved I didn’t have to take on the world with my law degree. Being here in this slower, more peaceful atmosphere shows I have something more to offer.”