Harper Lee had plans to write a string of novels after To Kill A Mockingbird, a letter the author wrote before the book was published has revealed.

In the letter, sent two years before To Kill A Mockingbird came out in 1960, she listed six ideas that she thought would occupy her for the next 15 years.

Harper Lee has not written a full novel since To Kill A Mockingbird‘s success.

However, a manuscript she wrote before that book, Go Set A Watchman, has been found and will be published next week.

Harper Lee wrote Go Set a Watchman in the mid-1950s – but her editor persuaded her to turn some of the story’s flashback sequences into a separate novel.

That novel became To Kill A Mockingbird, which went on to win the Pulitzer Prize in 1961 and is regarded as one of the greatest novels of the 20th Century.

In 1958, Harper Lee wrote to her friend Joy Brown who, along with her husband Michael, had given her money to leave her job and focus on writing.

Harper Lee told them she was trying to finish “My Novel”. She described it as “the hardest damn thing to write I’ve ever attempted” and added: “I’m about six weeks’ gone with another one.”

The author then went on to list ideas for future books.

“I have my work cut out for me for the next fifteen years:

• (1) Race Novel
• (2) Victorian Novel
• (3) What Mr. Graham Greene calls An Entertainment
• (4) I’m gonna tear Monroeville to pieces (1958 Monroeville)
• (5) A Novel of The United Nations
• (6) India, 1910

“Can you feed and lodge me so long?” Harper Lee then asked.

The absence of any novels by Harper Lee in the last 55 years means Go Set A Watchman is one of the most hotly anticipated releases in publishing history.

It is known that Harper Lee did attempt to write more after To Kill A Mockingbird.

The New Yorker recently documented that, in the late 1970s, Harper Lee worked on a true crime novel titled The Reverend, about an Alabama preacher who was accused of five murders.

However, Harper Lee dropped the idea because she said she did not “have enough hard facts about the actual crimes for a book-length account”, The New Yorker reported.