Who developed the first spell checker?

The first spell checker is widely attributed to Peter B. Lewis, who developed it in 1971 while working at IBM. His program, called "Correct", was designed to identify spelling errors in documents and suggest corrections.

While Lewis's work was a major breakthrough, it's important to note that earlier forms of spell checking existed. For example, Samuel Johnson created a dictionary in 1755 that could be used to verify the spelling of words. However, Lewis's program was the first to be fully automated and integrated into a computer system.