This week, Senator Jeanne Shaheen of New Hampshire introduced the Women on the Twenty Act, legislation aimed at putting an American woman on the $20 bill. Shaheen's efforts nod to an initiative by Women on 20s, a group that is lobbying to change the $20 by 2020. That year Americans will mark the 100th anniversary of the passage of the 19th amendment, which granted women the right to vote. (The $20 is also overdue for a redesign to thwart counterfeiters.) For Andrew Jackson, current face of the $20 bill, this is the latest assault on the paper perch he has...