The nickel passed to Walton's sister, Melva Givens, after experts said the odd date on the coin suggested it was a fake.

BBC: Rare Liberty Head nickel sells for $3.1m

One of Walton's heirs, his sister, Melva Givens of Salem, Va.

WSJ: Rare 1913 Nickel Auctioned for $3.1 Million

Melva Givens put the coin in an envelope and stuck it in a closet, where it stayed for the next 30 years until her death in 1992.

WSJ: Rare 1913 Nickel Auctioned for $3.1 Million