Many Americans were pleasantly surprised Wednesday to learn that Harriet Tubman, a former slave-turned-abolitionist who led thousands of slaves to freedom through the Underground Railroad, has been chosen to replace Andrew Jackson on the face of the $20 bill. Treasury Secretary Jacob J. Lew made the announcement following months of talk that a woman would be on U.S. currency for the first time since Martha Washington in the late 19th century.

Watch the cast of Underground explain why you've never seen slavery like this

The news held special significance for the cast and producers of the WGN America show Underground — a thriller that chronicles a group of slaves' daring 700-mile escape from a plantation in Georgia to freedom. Lead actors Jurnee Smollett-Bell and Aldis Hodge tweeted out their excitement, while series creators Misha Green and Joe Pokaski reveled in the news. "I just think it's about time," said Pokaski. "When you open your wallet you're more conscious of American history. I hope [the Railroad] is something people understand more."

So should we expect to see Tubman on Underground too? After a strict no-spoiler policy in place since the show debuted in March, the producers did relent and share some intel. "There's no way you can tell the story of the Underground Railroad without the story of this superhero," Green said. They wanted to start the series with the characters they crafted as heroes first, she said, but other historical figures — including Frederick Douglass and Henry Box Brown, the Virginia slave who famously shipped himself to freedom in Philadelphia in 1849 — will be weaved into the story in coming seasons if it gets renewed.

Go behind the scenes of Underground with John Legend

They even have some actresses in mind to play Tubman, they said, but stuck to their policy when pressed. "We plead the Fifth on that one," Pokaski said.

Who do you think should play Harriet Tubman? We vote for Oscar winner Octavia Spencer, who has already (sort of) played the role... twice.