A collection of 1871 Boston Red Stockings memorabilia was valued at $1m in a recent episode of Antiques Roadshow.
The hoard was evaluated during filming in New York on January 3. It's the most valuable sport item ever to appear on the long running TV show.
It was brought in by a woman who had inherited it from her great-great grandmother, the owner of a guesthouse in the 19th century.
The Red Stockings had stayed there for a time after moving from Cincinnati in the 1870s.
She explained: "It was just sitting in here 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."
The collection includes a set of baseball cards, which are among the earliest examples known.
Expert Leila Dunbar described the collection as "the greatest archive she's seen at the roadshow.
"When you look at memorabilia and you value it, you look at the historical importance of the players, of the team, of the era, of the event.
"You also look at rarity, you look at condition, you look at provenance. And this has it all."
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