Harper Lee is being awarded America's highest civilian honor, the Presidential Medal of Freedom, for her outstanding contribution to literature. Her only novel, To Kill a Mockingbird, won the Pulitzer Prize in 1961 and is ranked by the Guinness Book of World Records as the top selling novel of all time. The novel has sold more than 30 million copies. Last week, To Kill a Mockingbird won the Quill Award for best audiobook of the year for its belated debut on audio.

According to the citation, Lee is being honored for "an outstanding contribution to America's literary tradition. At a critical moment in our history, her beautiful book, To Kill a Mockingbird, helped focus the nation on the turbulent struggle for equality."

The award will be presented to Lee during a ceremony at the White House on Monday, November 5. The ceremony will also honor 1992 Nobel economics prize winner Gary Becker; Human Genome Project leader Francis Collins; civil rights leader Benjamin Hooks; and former House Foreign Affairs committee chairman Henry Hyde.

The Medal of Freedom was established by President Truman in 1945 to recognize civilians for their efforts during the second world war. President Kennedy reinstated the award in 1963 to honor distinguished service.