Harper Lee, author of To Kill A Mockingbird, has died at age 89.

Lee was born in Monroeville, Alabama on April 28th, 1926, and published her famed novel in 1960 after spending several years in New York, basing a number of characters in the book on friends (including Truman Capote) and family from her hometown. To Kill A Mockingbird has since become widely regarded as a classic work of American literature, due in part to its bracing look at racial injustice in the Deep South during the Great Depression. Atticus Finch, the father figure and attorney whose stalwart defense of a black man wrongly accused of murder earned him accolades for being one of the best fictional characters in literature, was based on Lee's own father, Amasa Coleman Lee.

For decades, To Kill A Mockingbird was Lee's only published work. But last year, Harper Collins published Go Set a Watchman, a novel that was apparently the initial story Lee submitted to her editor back in the 1950s before it was shaped into Mockingbird. Watchman was criticized for its depiction of an older Atticus Finch, who NYTimes reviewer Michiko Kakutani called "a racist who once attended a Klan meeting, who says things like 'The Negroes down here are still in their childhood as a people.' Or asks his daughter: 'Do you want Negroes by the carload in our schools and churches and theaters? Do you want them in our world?'”

Lee suffered a stroke in 2007 and had been living in an assisted living facility for the last few years. The state of Alabama briefly conducted an investigation into whether or not Lee had been mentally sound when she agreed to publish Watchman. Officials found no wrongdoing.

A stage production of To Kill A Mockingbird is expected to debut on Broadway next year, with a script written by Aaron Sorkin.