For the first time in more than a century, a woman’s face will appear on an American bill.

The Treasury Department announced Wednesday it will replace the main image of its own founder, Alexander Hamilton, on the $10 bill, with a woman as yet to be determined. Mr. Hamilton will remain on the bill in a diminished way.

The currency will be unveiled in 2020, the 100th anniversary of the 19th Amendment giving women the right to vote. The last woman to appear on a bill was Martha Washington, in the late 19th century.

Americans will have the summer to weigh in on which one of history’s leading ladies they think should have the honor. There is no list of successors, but names frequently mentioned include Eleanor Roosevelt, abolitionist Harriet Tubman, civil-rights icon Rosa Parks and Wilma Mankiller, who served as principal chief of the Cherokee Nation.

“It’s very important to be sending the signal of how important it is to recognize the role that women have played in our national life and in our national history for a very long time, really from the beginning,” Treasury Secretary Jack Lew said in an interview Wednesday. “This is a symbolic representation of that but symbols are important.”