Who invented and built the first one man helicopter?

The first one-man helicopter was invented and built by Igor Sikorsky in 1940. This experimental aircraft, known as the Vought-Sikorsky VS-300, featured a single main rotor and a tail rotor for stability. It was a significant milestone in aviation history, demonstrating the feasibility of vertical flight for a single pilot. Sikorsky's work laid the foundation for future advancements in helicopter design.