Final answer:
Ira Levin was the author of "Rosemary's Baby" and "The Stepford Wives" and was born on August 27, 1929. He was known for his expertise in creating suspenseful novels.
Step-by-step explanation:
The author of "Rosemary's Baby" and "The Stepford Wives" who was born on August 27, 1929, is Ira Levin. He was referred to as "the Swiss watchmaker of the suspense novel" by Stephen King. Ira Levin was known for his mastery in creating suspenseful and thrilling stories that captivated readers.