article: One of America's greatest poets was honored by the US Postal Service in a star-studded ceremony on Tuesday. Maya Angelou, the acclaimed author of such classics as I Know Why the Cage Bird Sings and On the Pulse of Morning, which she read at Bill Clinton's inauguration in 1993, was issued a Forever stamp in honor of her many achievements and contributions. First Lady Michelle Obama and Oprah Winfrey were just two of the big names in attendance for the unveiling which gave the public a first look at the stamp, which features a picture of Angelou's face and one of her many memorable quotes. The problem however, is that the featured quote came from another author. Scroll down for video . A quote attributed to Maya Angelou on her commemorative stamp released by the US Postal Service is actually that of another writer . The stamp was unveiled Tuesday at an event featuring First Lady Michelle Obama and Postmaster General Megan J. Brennan (above) Maya Angelou, the acclaimed author of such classics as I Know Why the Cage Bird Sings and On the Pulse of Morning, was issued the Forever stamp for her contributions to the arts and this country . 'A bird doesn't sing because it has an answer, it sings because it has a song,' reads the stamp, a quote that has long been attributed to Angelou, with President Obama even using the famous line as he honored the poet at the 2013 National Medal of Arts and National Humanities Medal. What's more, The Washington Post found proof of an interview in which Angelou herself used the quote. Joan Walsh Anglund wrote in her 1967 book A Cup of Sun; 'A bird doesn’t sing because he has an answer, he sings because it has a song.' A few years before this quote first appeared though in 1969 with the publication of Angelou's aforementioned autobiography I Know Why the Cage Bird Sings, it was used in a children's book by another American author. Joan Walsh Anglund, now 89, wrote in her 1967 book A Cup of Sun; 'A bird doesn’t sing because he has an answer, he sings because it has a song.' In a statement released shortly after the origin of the quote was revealed, Postal Service spokesperson Mark Saunders said; 'The Postal Service used her widely recognized quote to help build an immediate connection between her image and her 1969 nationally recognized autobiography, ‘I Know Why the Caged Bird Sings.' Saunders later added in an email to the Post that had they been aware of this fact they would have selected another of Angelou's famous lines. Angelou, who was born into poverty, holding down jobs as a fry cook, singer, and at one point even a prostitute, passed away last May. She was 86-years-old at the time, and had written, among other works, seven autobiographies, countless poems, and numerous scripts for theater, television and film. She also continued to teach throughout her life, spending the last four decades of her life as a professor at Wake Forest in Winston-Salem, North Carolina. As for Anglund, she seems remarkably nonplussed about the entire incident. 'I think it easily happens sometimes that people hear something, and it’s kind of going into your subconscious and you don’t realize it,' she explained. There are no plans to remove the limited edition stamp at this time .
highlights: A quote attributed to Maya Angelou on her commemorative stamp released by the US Postal Service is actually that of another writer .
  'A bird doesn't sing because it has an answer, it sings because it has a song,' reads the stamp, a quote that has long been attributed to Angelou .
  Joan Walsh Anglund wrote the words in her 1967 book A Cup of Sun .
  Angelou, the acclaimed author of such classics as I Know Why the Cage Bird Sings, was issued the Forever stamp for her contributions to the arts .
  The stamp was unveiled Tuesday at an event featuring First Lady Michelle Obama, Oprah Winfrey and Postmaster General Megan J. Brennan .
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