The Indian Museum of North America at Crazy Horse Memorial has acquired a knife that reportedly belonged to Lakota leader Crazy Horse.

With funds from a benefactor, Museum Director Anne Ziolkowski purchased the knife and beaded sheath in telephone bidding to an auction gallery in Texas on April 19. She is marking her 25th year as museum director and says the knife is as historically important as the museum’s Manhattan trade beads from 1626.

Auction coordinators rated the knife, because of its extensive records, as the top item at a sale featuring 1,500 historic Western pieces. The gallery said its expert authenticated the knife and sheath, confirming that its design and materials were from the 1850s to 1900s.

Crazy Horse, “Tasunka Witko,” was born in the 1840s and died in 1877 at Fort Robinson, Nebraska, after being stabbed.

Crazy Horse Memorial Foundation, the museum’s parent organization, rarely buys items. Foundation President-CEO Ruth Ziolkowski said a supporter’s estate recently gave unrestricted funds to help the museum.

The $20,000 knife and sheath could be on display by Mother’s Day.