The U.S. Treasury Department announced that over the next four years it will mint quarters honoring 20 women who played important roles in the country's history. As part of those being honored, poet Maya Angelou has become the first African-American to be the face of a 25-cent coin in the United States. The first issues have already begun to be distributed to the country's banks.

Starting this week, Angelou will appear on the reverse side of the quarter while the other side continues to feature the portrait of the first president of the United States, George Washington. This series of coins is intended to diversify the images and references used on U.S. legal tender coins and banknotes.

The overall Treasury Department series celebrates four women in addition to Angelou, who are icons in the country's recent history in areas such as science, politics and culture: other than Angelou is Sally Ride, the first woman astronaut; Wilma Mankiller, the first woman chief of the Cherokee Nation; Anna May Wong, the first Chinese-American Hollywood star; and Nina Otero-Warren, a leader of the suffragette movement in New Mexico.

"Every time we do a redesign of a coin or a bill, we have the opportunity to say something about our countries — what we value, and how we have advanced as a society," Janet Yelle, secretary of the Treasury, said in a statement.

Angelou, who died in 2014 at the age of 86, was a poet, dancer, director and producer of musicals, plays, films and television programs for more than 50 years, and a social activist in defense of human rights.