(CBS News) A rare Honus Wagner card is among the valuable collection of century-old baseball cards found by an Ohio family in their grandfather's attic.
The cards found by Karl Kissner is "The most significant find in the history of the hobby," according to Chris Ivy of Heritage Auctions.
Kissner and his family inherited a turn-of-the-century house in rural Defiance, Ohio. Kissner found almost 700 little baseball cards tied in a neat bundle in a cardboard box sitting untouched for one hundred years in the attic.
"When they sent in the package, and we initially opened it, our reaction was, 'Oh my God, these are the nicest condition examples of this series that we've ever seen,'" Ivy said.
The cards were given-away as a candy promotion around 1910 and include such baseball luminaries as Ty Cobb, Cy Young, and Christy Mathewson.
Kissner assumes that his immigrant grandfather didn't know what to do with them, so he put them in the attic, and forgot about them. Today the cards are valued at about $3 million.
Cards like these are graded on a so-called PSA scale of one to ten. Kissner said he was told one of the cards was graded at a PSA ten. Which one? The Honus Wagner card, which Kissner called "The Mona Lisa of baseball cards."
The Kissner grandfather is survived by about 20 family members who will divide the windfall when the cards are auctioned off next month.
It's safe to say they'll be telling a story for generations about how a simple home cleaning turned into a financial home run.