Lewis died in 1963. Most of his books were written in the 1940s and 50s. He was a popular author during his lifetime, but since his death his books have sold increasing amounts. This is most true of the last 10 years. Why the appeal? With the occasion of the ten-year anniversary of HarperOne publishing Lewis's works, Mickey Maudlin of HarperOne suggests that Lewis has a "range of unique traits:"