Leonardo da Vinci created on paper, at least with the first helicopter, and the very first piloted helicopter was invented by Paul Cornu in 1907, however, this design was not successful. Another Frenchman, Etienne Oehmichen built and flew a helicopter 1 kilometer in 1924. An early practical helicopter that flew for a decent distance was the German Focke-Wulf Fw 61 invented by an unknown inventor. ( http://en.wikipedia.org/wiki/Focke-Wulf_Fw_61 )
Igor Sikorsky is considered to be the "father" of helicopters not because he invented the first. He is called that because he invented the first successful helicopter, upon which future designs were based. http://inventors.about.com/library/inventors/blhelicoptor.htm
So where did the RC model helicopter begin? Well I do not know who is credited with the First RC Model Helicopter, but it was in the 70's that the RC Helicopter revolution really began.
For the most part, they were all Nitro powered, using standard model Airplane engines (40 and .60 size) and 4-6 channel airplane radios.
Using a 4 channel radio to control the 5 functions of a model helicopter was quit unique in it challenges and results. What they did was used a "Y" connector for the throttle and pitch servo. Then you mechanically set up the throttle and pitch curve on the heli.
In the '70's there were 2 basic type of Helis, the teetering head, fixed pitch and soon after came the collective pitch. And just like today, some had direct drive tail rotors systems while other went with belt drive.
The first of these Heli's where hard to fly, had very poor control and lacked any tail gyros, radio mixing or any of the modern connivances that make today's Helis fly so well and easy. We even had to mechanically set the lead / lag of the main blades, until we just left off 2 of the 3 bolts on the main blades and let them seek there our lead / lag.
But the RC Model helicopter matured quickly and by the '80's the RC Model Helicopter could fly quite nicely, the radio manufacturers started making good Helicopter Radios, the Helicopters themselves had the modern style Bell / Hiller control system, single point Main Blade attachment for self Lead / Lag and gyros became common place. Direct drive or belt drive tail rotors still were used.
In the '80's and' 90's the Far East began to create beautiful Models of all sizes. And the "Ready To Fly" models became common place. The race was one and the things they started doing with the RC helicopter was only limited by ones imagination.
I would think that this century is know as the "Age of Electrics" and today you can get an Electric Helicopter in any size, (small enough to fix it your hand) to 40-60 size.
And they can ever fly, they are competitive with your fuel choppers, only quiet and no smoke, no starting equipment needed and are fully 3D capable.
So if you're flying interest lean toward the rotary wings birds, check out the new electrics. They make then so simple today that you can buy one, open the box, and charge the batteries and fly, even if you have never flown before!