Leila Dunbar, right, celebrates after the $1 million appraisal of rare Boston Red Stockings baseball cards on Antiques Roadshow.

These are not your ordinary baseball cards.

A collection of rare cards featuring Boston Red Stockings players from the 1870s received a $1 million appraisal at the Saturday taping of Antiques Roadshow, according to the Daily Mail, the highest antique appraisal ever to be made on the public TV show.

The cards are owned by a New York resident who received a $5,000 offer previously for them. She inherited them from her great-great-grandmother who ran a Boston boarding house in the late 1800s that housed some of the first professional baseball players of the time, Daily said.

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The most valuable piece in the rare collection may be a May 1871 letter to the great-great-grandmother that includes hand-written notes from three future Hall of Fame stars: Albert Spalding and brothers Harry Wright and George Wright.

'I'm hoping they'll stay in the family,' the owner said.

Read the coverage on the Daily Mail.