"I cant express to you how grateful we are for all of this," Jane Donovan, James' oldest daughter tells PEOPLE

By Michael Miller
Updated October 30, 2015 07:15 PM
Credit: Jaap Buitendijk/Disney

After decades of waiting for their father’s incredible life story to be shared with the world, James Donovan’s children are finally seeing the man get his due.

“I cant express to you how grateful we are for all of this,” Jane Donovan, James’ oldest daughter tells PEOPLE. “So many years have gone with nothing and I thought, ‘Wait a minute, we had an amazing father here, he did so much for this country.’ We almost gave up hope.”

The tale of Donovan’s unpopular defense of Russian master spy Rudolf Abel in 1957, and the events that led him to negotiate his release in exchange for downed U-2 spy pilot Gary Powers years later, is now the subject of Steven Spielberg’s Bride of Spies, in which Tom Hanks plays Donovan.

“I don’t know how to thank this man,” Mary Ellen Donovan, James’ youngest daughter says of Hanks’ performance in the film.

Donovan’s story was rescued from obscurity by screenwriter Matt Charman, who discovered the late insurance lawyer in the footnote of a Cold War book.

After interviewing Donovan’s son, Charman says he came to realize Donovan “had been a quiet guy who wasn t showy or flashy, and that in a way history had never quite realized how remarkable he had been.”

Mary Ellen, who’s seen the movie three times now, says that each viewing brings a new wave of overwhelming emotions.

“I was pretty much sobbing because it just brought home the fact that my father s been like a big secret all these years, and I was just so proud of him and proud for him to have this opportunity for his name and everything he accomplished to be known.”