'Women on 20s' to Ask President Obama to Put One of These 4 Women on $20 Bill

"Women on 20s" campaign wants to replace Andrew Jackson with a woman.

— -- A woman could soon be the new face of the U.S. $20 bill.

"In the past 48 hours since the final round started, we’ve had 60,000 people cast votes already," the group's executive director, Susan Ades Stone. told ABC News today. "Though all these women and many more deserve to be honored, the winner will be a symbol of what we hope are greater things to come."

Here are key facts and fun trivia on the final four women, according to their bios on "Women on 20s," to help inform your vote.

1. Eleanor Roosevelt, First Lady

- Roosevelt was the first U.S. president’s wife to take "an activist role and present her causes directly to the people through her own press conferences, syndicated columns and radio broadcasts."

- She was "deeply influenced by the feminist headmistress" at the boarding school she attended in London at 15.

2. Harriet Tubman, Abolitionist

- Tubman "returned to the South an estimated 19 times" to lead slaves to freedom to the North via the Underground Railroad.

- During the Civil War, Union soldiers relied on Tubman, who served as a spy and scout, to "guide them when poorly drawn and outdated maps could not."

- The Quaker Thomas Garrett said of her, "If she had been a white woman, she would have been heralded as the greatest woman of her age."

- After the war, Tubman "advocated for education and property for freed slaves in the South and she cared for the elderly and poor."

- After her death in 1913, she was nicknamed "General Tubman" "and laid to rest with military honors –- one of the first recorded African-American women to serve in the military."

3. Rosa Parks, Civil Rights Activist

- Parks became known as "the mother of the freedom movement" after refusing to move to the back of the bus for a white passenger in Montgomery, Alabama, in 1955.

- At the time of her arrest afterwards, she was the secretary for the Montgomery chapter of the NAACP and had "recently attended leadership training in workers' rights and racial equality."

- President Obama has said of her, "In a single moment, with the simplest of gestures, she helped change America and changed the world. ... She takes her rightful place among those who shaped this nation’s course."

4. Wilma Mankiller, Cherokee Nation Leader

- Mankiller was the "first elected female chief of a Native nation in modern times."

- She "advocated for extensive community development, self-help, education and healthcare programs that revitalized the Nation of 300,000 citizens."

- Mankiller's "family name refers to a traditional Cherokee rank."

- Mankiller has also taught at Dartmouth College as a guest professor.

After the voting period ends (an end date has yet to be decided), the "Women on 20s" campaign will ask President Obama to start the process of getting the winning woman on the bill, Stone said.