While the idea of vertical flight and helicopters has challenged inventors since at least the days of Leonardo da Vinci, some of the earliest success occurred at College Park in the 1920s.
Emile Berliner
When Emile Berliner became interested in helicopters in 1908, he was already a successful inventor, having invented the gramophone, the telephone transmitter (mouthpiece) and other devices. In 1912, Berliner came to College Park as a sponsor of the Washington Aeroplane Company. However, Berliner continued working on his helicopter ideas at his home and factory in Washington, DC. In 1919, his son, Henry, joined Emile on the helicopter project. Henry took over most of the experimental operation when they moved the project to College Park the next year.
Early Attempt
The initial machine had 2 contra-rotating propellers, a 4-wheeled chassis, engine, shutter-like vanes, rudder, a seat for the pilot, and little else. While the machine rose quite easily from the ground, there was still a need for more lateral control and a more powerful engine.