'Antiques Roadshow' -- 1870s Baseball Cards Found In NYC ... Worth $1 Million!

Screw your 1989 Ken Griffey Jr. Upper Deck rookie card ... an old woman from Boston just learned her family's been sitting on a MILLION DOLLAR baseball card stash for more than 100 years!

The woman -- who has not revealed her name -- went on PBS' "Antiques Roadshow" with a bunch of cards and memorabilia she inherited from her great-great-grandmother.

Turns out, the booty was a collection of ultra-rare baseball cards featuring the 1871 Boston Red Stockings. The woman also had autographs from some of the players.

One of the cards featured George Wright -- the biggest superstar in the sport at the time. He was ultimately inducted into the Baseball Hall of Fame.

"Roadshow" appraisers valued the collection at $1 million.

The woman says she found the collection just sitting in a desk drawer ... "I ran across it one day and decided I'd like to have it, not realizing at all what it was worth."