No woman is depicted on U.S. paper currency. This makes our money a bit exceptional among the banknotes of our international peers, several of which — including Britain, Canada, Australia, Japan and Mexico — have emblazoned paper money with various national heroines’ portraits. In this country, suffragist Susan B. Anthony and the Native American explorer Sacagawea grace little-used dollar coins, but it’s not quite the same. So an Internet movement calling itself “WomenOn20s” has started crowd-sourcing the selection of a proposed female replacement for President Andrew Jackson on the $20 bill — to be followed by an actual request for a substitution to President Barack Obama. It might actually come to pass. Obama has expressed broad sympathy with the idea, and he has full legal authority, through the secretary of the Treasury, to order a redesign.