A piece of a family's personal history had been forgotten about, until now.

It all started when Jean had written a letter to her sister, while she was trying to make it in the big city.

"She was in college and I was in Kansas City," said Castle.

A letter like this is a treasure, not only to her, but also to her son Roger.

"To hear stories about my mother wearing high heels and interviewing for a job and going to a modeling school, my sisters and I were just howling at that," said Roger.

But this letter has a much bigger story to it than just his mom's adventures back in the 1940s.

Roger first got ahold of it after his Aunt Lodell, Jean's sister, passed away.

"Either my uncle or my cousin got it out and said, 'Have you heard about this?'" Roger told Next.

The letter, almost 70 years old, arrived at Lodell's not long ago, with another note attached.

"It just says, 'We strive to constantly protect and ensure timely mail delivery to our customers and they apologize,'" he read.

It goes on to explain that while someone was cleaning the Kansas City post office, that person found the letter - undelivered.

"It's pretty crazy when you think about it. Seventy years later. How it could be in a mail bag that nobody had seen or touched in 70 years," said Roger. "Somebody went to obviously a great effort to track her down."

And it was a great effort to finally deliver it to her.

"The stamp on the envelope was 3 cents. And the postal service sent it to my aunt in Priority Mail express spent 22 dollars and 92 cents to get it to her," he told us.

For Roger, this letter is a treasure. For Jean, she's a bit ornery.

"She made some sarcastic comment about how long it had taken them," Roger said about her reaction to receiving the lost letter.

"I don't think very much of the post office," she said.