What year was the helicopter invented?

The first successful helicopter was the Focke-Wulf Fw 61, whose first flight was June of 1936 in Germany. The man often credited with being the inventor of the helicopter is Igor Sikorsky, whose version first flew on September 14, 1939.

Igor Sikorsky's VS-300 was built by the Vought-Sikorsky Aircraft Division of the United Aircraft Corporation in Connecticut. Its first flight was tethered. The first free flight took place May 13, 1940.

Before the helicopter as it is known today, a more primitive rotorcraft called a giroplane was successfully flown on January 17, 1923. Designed by Juan de La Cierva of Spain, it used a single main rotor and rotor tail and was used during the 1930s by the Spanish military.