U.S. Treasury Secretary Janet Yellen just made history with a wave of her pen.
- This week, the Treasury Department unveiled the first U.S. dollars to sport Yellen's signature, instead of that of her predecessor Steven Mnuchin.
- The $1 and $5 bills will be the first U.S. currency to bear the signature of a female Treasury Secretary.
- The bills also include the signature of Treasurer Chief Lynn Malerba - the first Native American to hold that role.
- The new bills will go into circulation next month.