(This post was last updated at 6:15 p.m. EDT.) Treasury Secretary Jacob Lew announced on Wednesday that the countenance of abolitionist leader Harriet Tubman will grace a new $20 bill.The decision caps a public campaign asking for a woman to be placed on American paper currency and months of deliberation by the Treasury to replace either Alexander Hamilton on the $10 bill or Andrew Jackson on the $20 bill."With this decision, our currency will now tell more of our story and reflect the contributions of women as well as men to our great democracy," Lew said in a letter to the American people.The decision also speaks to the diversity of the U.S., says Lonnie Bunch, the founding director of the Smithsonian's National Museum of African American History and Culture."For me, having Harriet Tubman on the $20 bill really says, first of all, that America realizes that it's not the same country that it once was — that it's a place where diversity matters," Bunch told All Things Considered. "And it allows us to make a hero out of someone like Harriet Tubman, who deserves to be a hero."In a statement, the Treasury also announced that the new $20 note will keep an image of Jackson, who was a slaveholder, on the back. The new $10 bill will keep Hamilton on the front but in the back feature "an image of the historic march for suffrage that ended on the steps of the Treasury Department." Leaders of that movement — Lucretia Mott, Sojourner Truth, Susan B. Anthony, Elizabeth Cady Stanton and Alice Paul — will be honored in the image.As we've reported, last year, an unofficial contest by the activist group Women on 20s gave the nod to Tubman to take Jackson's place on the $20 bill. The campaign then sent a petition to President Obama.As we reported: