WASHINGTON – Maya Angelou’s smiling face greeted members of the crowd as they entered the Warner Theatre on April 7.

The late African-American author was honored by the United States Postal Service with postage stamp as part of its forever collection. Posters of the stamp adorned the theater and the state during a ceremony.

The stamp shows Ross Rossin’s 2013 portrait of Angelou, which can be seen in the Smithsonian Institution’s National Portrait Gallery. It also features a quote from an interview she gave: “A bird doesn’t sing because it has an answer, it sings because it has a song.”

The sheet of stamps includes a quote,”Try to be a rainbow in someone’s cloud,” from Angelou’s book “Letter to My Daughter.”

Anglou’s best-known work is her memoir “I Know Why the Caged Bird Sings.”

The stamp was designed by Ethel Kessler of Bethesda, Md.

With the Angelou stamp, there are now 181 women featured on stamps, 37 of whom are African-Americans.

The unveiling ceremony of the stamp was attended by first lady Michelle Obama, Oprah Winfrey, Attorney General Eric Holder, Postmaster General Megan Brennan and Angelou’s son and grandson, Guy and Colin Johnson.

“Doctor Angelou certainly had a song in her,” Brennan said. She is the first female postmaster general. She started her term in February.

Angelou’s son, Guy Johnson, said that his mother left a stamp on everything she touched. “It is only fitting that the U.S. Postal Service is bringing out a stamp in recognition to her life’s work,” he said.

Johnson spoke about his mother’s difficult childhood before handing the microphone to his son, Colin, who said that continuing his grandmother’s legacy was easy because of what she had done.

Brennan said Angelou’s work embodied her personal struggle, but also the triumph of courage and the human spirit.

Angelou came from poverty, fought against segregation and violence and became one of the most important American authors of the 20th century. She died in May at age 86.

Winfrey said that it was “incredible” that the stamp was happening and thanked the Postal Service for doing it.

Halfway through her speech, a wide-spread power outage in downtown Washington cut the lights in the theater. The television personality continued talking.

“This new forever stamp serves as a tribute to humanity and contribution to our nation,” Brennan said.

There was controversy regarding the stamp. The Washington Post reported that the quotation on the stamp, attributed to Angelou on several occasions, might not be hers.

The quote was attributed to Angelou by President Barack Obama when he presented her with the  the Presidential Medal of Freedom in 2011. Angelou won the National Medal of Arts in 2000 and two Grammys for spoken word albums, among many other honors.

She used the quotation in an interview.

The original quote is from the book “A Cup of Sun” by the children’s book authorJoan Walsh Anglund. The book came out in 1967, two years before Angelou’s “I Know Why the Caged Bird Sings.”

None of the speakers acknowledged the controversy during the ceremony.

Brennan called the words on the stamp “joyous words of inspiration.”

Reach reporter Alicia Alvarez at [email protected] or 202-408-1489.