All seven of our current bills ($1, $2, $5, $10, $20, $50 and $100) could be converted to be a 50-50 bill. That means that half of the $1 would always have George Washington on it; the other half would be printed with another historic American on it.
Secondly, we could ensure that the new faces provide additional diversity, for example by requiring that the other people on a $1 or $100 would always be a woman, on a $2 or $20 a man, and on a $5 or $50 an African-American. We could also ensure that Hispanic-Americans, Asian-Americans, Native Americans, etc., are represented. I suggest that the two new faces on the $5 or $50 have played a role in helping end slavery in America, as Presidents Lincoln and Grant did.
A third suggestion would be to have a national commission (with two members from the House, two from the Senate, and one appointed by the president) to take the nominations from people or groups on whom to place on the bills. That commission would have public hearings and then send its recommendations to Congress for approval.
A fourth suggestion is that because the $10 has a non-president on it now that the other 50 percent would have a former president or former member of the Supreme Court placed on it. Some ideas include Sandra Day O’Connor, the first woman to be on the Supreme Court; Thurgood Marshall, the first African-American on the Supreme Court, or former Presidents Jimmy Carter, George H.W. Bush, Barack Obama, Theodore Roosevelt, Dwight Eisenhower or others.
The final suggestion is that the decisions would be made at the end of each decade with the new bills printed for the following 10 years. Every decade the commission would decide to place a new historic American on the bill or keep the existing one for 10 more years. Remember, people do use older bills, so they could still see the first person placed on it; many would like to save one bill for themselves.
This could expand our history and our appreciation of the actions of Americans on the past. Doing it as a 50-50 could help to keep happy those who love the current person on the bill and also help those who want a new person on the bill; both would get their way.
This is not unprecedented. In Europe, the faces on Euro bills vary from country to country, but the value remains the same.