Being important is certainly a criteria for being on currency, but it's not the only one. It's also intended to honor people and their achievements. And the magnitude of an achievement is measured both by its influence, and by the its influence relative to the obstacles faced. It's also an expression of ideals, even (especially?) those we don't always live up to. By those standards, Harriet Tubman makes for a fine choice: her actions faced tremendous obstacles and express core American ideals.
I do think it's unfortunate that the person was decided after the gender, though. That really sends the wrong message. "Let's put Harriet Tubman on the ten" is a good idea. "Let's put a woman on the ten, but we'll figure out who later" reeks of political calculation, and it only distracts from the life and work of the extraordinary woman chosen for the honor.
I do think it's unfortunate that the person was decided after the gender, though. That really sends the wrong message. "Let's put Harriet Tubman on the ten" is a good idea. "Let's put a woman on the ten, but we'll figure out who later" reeks of political calculation, and it only distracts from the life and work of the extraordinary woman chosen for the honor.