(CNN) Supporters of an Obama-era plan to put abolitionist Harriet Tubman on the $20 bill were disappointed last week by news that the Treasury Department has delayed the bill's redesign.

But artist Dano Wall decided not to wait for the Trump administration to honor the Underground Railroad hero. He has created a stamp that can be used to superimpose Tubman's image over President Andrew Jackson's portrait.

Wall created the stamp in 2017 with the intent of getting Tubman on the bill as soon as possible. In February of that year, he gave about 100 stamps to his friends before opening an Etsy shop to sustain the costs.

But the stamp has soared in popularity in the last week after Treasury Secretary Steven Mnuchin said Wednesday during a House Financial Services Committee meeting that he hasn't made any decisions about the redesigning the bill. Mnuchin told the committee that decisions about the imagery on the $20 "will not be an issue that comes up until most likely 2026."

Mnuchin's predecessor, Treasury Secretary Jack Lew, announced in 2016 that the US would swap out Jackson, the slave-owning president whose legacy is synonymous with the Trail of Tears, with Tubman. Under Lew's plan, Tubman -- an escaped slave who would be the first black woman featured on official US currency -- would be on the face of the bill and Jackson moved from the front of the $20 to its back.

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