Harper Lee had two books published in her lifetime.  The first To Kill a Mockingbird, published in 1960, became a best seller, widely read for its social convictions and the vivid account of childhood in a small Southern town.  The release of the film version in 1962 starring Gregory Peck only added to the fame of the book.  People waited in anticipation for more work from Lee.  However, Lee retreated to her hometown, Monroeville in southern Alabama, where she lived a quiet life with her sister.

Her second book Go Set a Watchman published in 2015, a year before her death, was far more contentious.  Written before the classic To Kill a Mockingbird, many felt the aging Lee had been taken advantage of and would not have wanted it published.

Payne, Tom. "Harper Lee." A-Z of Great Writers, Carlton Books, 1997, p. 206.